Primarni cilj ovog rada bio je istražiti koje su odrednice društvenog kapitala povezane s dobrostanjem adolescenata tijekom pandemije bolesti COVID-19. Istraživanje je obuhvatilo 317 sudionika koji su tijekom 2021. godine pohađali završni razred srednjih škola (gimnazijskog i strukovnih smjerova) iz četiri najveća grada u Republici Hrvatskoj: Zagreb (n=82), Split (n=80), Rijeka (n=65), Osijek (n=90). Sudionici su bili u dobi između 17 i 20 godina. Podaci su prikupljeni tako što su sudionici istraživanja ispunjavali anketni upitnik pod nazivom „Društveni kapital i subjektivna procjena dobrostanja adolescenata tijekom pandemije bolesti COVID-19“ koji se je sastojao od četiri dijela. U prvom dijelu upitnika sudionici istraživanja ispunjavali su demografske podatke, subjektivnu procjenu vlastitog zdravlja i razinu obrazovanja oba roditelja. Drugi dio upitnika sastojao se od globalno korištenog Kesslerovog upitnika koji procjenjuje rizik od razvoja mentalnih poremećaja. Treći dio upitnika sastojao se od pitanja za procjenu tjelesne aktivnosti učenika u uobičajenom tjednu (GPAQ), a četvrti dio upitnika procjenjivao je društveni kapital u obitelji, susjedstvu i školi upitnikom društvenog kapitala. Uz kvantitativne metode istraživanja primijenjena je i kvalitativna metoda u obliku polustrukturiranog intervjua licem u lice. Iz svakog grada obuhvaćeno je po šest sudionika. Ukupno su odabrana 24 sudionika i to slučajnim odabirom. Po šest iz Zagreba, Splita, Rijeke i Osijeka tako da su obuhvaćeni gimnazijski, strukovni tehnički i obrtnički obrazovni programi. Kombinirana metodologija istraživanja ponudila je dublju analizu u razmišljanja sudionika o temi društvenog kapitala i subjektivne procjene dobrostanja tijekom pandemije bolesti COVID-19. Za sve kategorijske varijable izračunate su frekvencije, a za set zavisnih varijabli društvenog kapitala izračunati su osnovni statistički parametri (aritmetička sredina (AS), standardna devijacija (SD), minimalni rezultat (MIN), maksimalni rezultat (MAX), medijan (MED), mjera asimetrije (A3), mjera zakrivljenosti (A4)) i Kolmogorov-Smirnovljev test normaliteta distribucije. Zbog standardnih problema s mjernim karakteristikama varijabli na skali Likertovog tipa svim navedenim zavisnim varijablama priloženi su histogrami frekvencija. Razlike između grupa u kategorijskim varijablama SPOL i razina obrazovanja roditelja (ROR) prema setu varijabli društvenog kapitala izračunate su Mann-Whitney U testom. Razlike između grupa u kategorijskim varijablama GRAD i obrazovni program (OP) prema setu varijabli društvenog kapitala izračunate su Kruskal-Wallis testom. Razlika između kategorijskih varijabli SPOL, GRAD, OP i ROR u odnosu na kategorijsku varijablu ZDRAVLJE izračunata je Pearsonovim hi-kvadrat testom, a povezanost među varijablama je izračunata koeficijentom kontigencije. Razina značajnosti promatrana u svim navedenim testovima korigirana je Bonferonijevom korekcijom za kontrolu Family wise error rate (FWER). Povezanost varijable ZDRAVLJE sa setom varijabli društvenog kapitala u obitelji, zatim varijable RIZIK sa setom varijabli društvenog kapitala u susjedstvu, te varijable tjelesna aktivnost (TA) sa setom varijabli društvenog kapitala u školi istražena je sigmoidnom funkcijom logističke regresijske analize. Logističkom regresijskom analizom izračunate su i vrijednosti omnibus testa, Hosmer i Lemeshow testa, Cox i Snellov i Nagelkarkeov koeficijent determinacije, ukupni postotak uspješne klasifikacije prediktivnog modela u odnosu na nul model, te su izračunati koeficijenti regresijske jednadžbe i njihova razina značajnosti. Podaci su obrađeni s programima Microsoft Excel (verzija 2017) i TIBCO Statistica (verzija 13.5), uz izuzetak logističke regresijske analize koja je obrađena programom IBM SPSS Statistics (verzija 23). Rezultati upućuju da su podrška i ohrabrenje roditelja, te zajedničke obiteljske aktivnosti povećale percipiranu vrijednost subjektivne procjene zdravlja kod adolescenata. Također, podrška obitelji koju doživljavaju adolescenti tijekom pandemije bolesti COVID-19 pozitivno je povezana sa zdravim životnim stilovima članova uže obitelji. Rezultati neformalne društvene kontrole sugeriraju kako većina sudionika ne doživljava svoju okolinu kao oslonac za zaštitu i unaprjeđenje mentalnog zdravlja tijekom pandemije bolesti COVID-19. Razina međusobne povezanosti među učenicima pozitivno utječe na ukupnu razinu tjelesne aktivnosti. Naime, sudjelovanje u izvannastavnim aktivnostima ili strukturiranim aktivnostima unutar škole za 37% povećava vjerojatnost visoke tjelesne aktivnosti učenika. Rezultati su pokazali da je tijekom pandemije bolesti COVID-19 u domeni društvenog kapitala u obitelji podjela rada u kućanstvu neravnopravna uz puno veći angažman djevojaka. Razlika prema spolu primijećena je i kod veće potrebe za razgovorom o događajima iz škole kod djevojaka. Rezultati društvenog kapitala u školi ukazuju da učenici gimnazijskih razreda najviše participiraju u izvannastavnim školskim aktivnostima, a najmanja angažiranost primijećena je kod učenika obrtničkih programa. Također, učenici koji pohađaju gimnazijski program više se druže sa školskim kolegama u slobodno vrijeme, dok je najmanja socijalna interakcija sa školskim kolegama uočena kod učenika koji pohađaju obrtnički program. Društveni kapital susjedstva upućuje da učenici čiji su roditelji niže razine obrazovanja susjedstvo percipiraju kao sigurnije mjesto u odnosu na predodžbu sigurnosti susjedstva kod učenika čiji su roditelji višeg stupnja obrazovanja. S obzirom na mjesto stanovanja statistički značajnih razlika nema između sudionika istraživanja po varijablama društvenog kapitala i subjektivne procjene zdravlja. Razlike u samoprocjeni zdravlja prema spolu upućuju da je pandemije bolesti COVID-19 negativno utjecala na zdravlje djevojaka. Kombinirana metodologija istraživanja je potvrdila kvantitativne podatke te pružila dublju analizu sudionika kroz primjenu polustrukturiranih intervjua licem u lice, što je rezultiralo boljim razumijevanjem njihovih razmišljanja o društvenom kapitalu i subjektivnoj procjeni dobrostanja tijekom pandemije COVID-19. Ovo istraživanje daje prikaz učinaka društvenog kapitala na dobrostanje adolescenata tijekom pandemije bolesti COVID-19 i temeljne mehanizme koji objašnjavaju te učinke. Rezultati ovog istraživanja ukazuju da snažne društvene veze i norme reciprociteta mogu olakšati upravljanje u kriznim situacijama, te potaknuti pojedince i zajednice na prilagodljive oblike ponašanja u cilju zaštite i unaprjeđenja dobrostanja adolescenata. S obzirom na dinamičnu prirodu pandemije bolesti COVID-19 i moguće nove varijacije sojeva virusa, doprinos ovog istraživanja obogaćen je relevantnim preporukama za očuvanje i unaprjeđenje dobrostanja adolescenata. The primary objective of this study was to explore the determinants of social capital associated with the well-being of adolescents during the COVID-19 pandemic. The research included 317 participants who were in their final year of high school (gymnasium and vocational programs) in four major cities in the Republic of Croatia: Zagreb (n=82), Split (n=80), Rijeka (n=65), and Osijek (n=90). The participants were between 17 and 20 years old. Data were collected through a questionnaire titled „Social Capital and Subjective Assessment of Adolescent Well-being during the COVID-19 Pandemic“, which consisted of four parts. In the first part of the questionnaire, research participants provided demographic information, self-assessment of their health, and the educational level of both parents. The second part of the questionnaire consisted of the globally used Kessler Psychological Distress Scale, which assesses the risk of developing mental disorders. The third part of the questionnaire included questions to assess students' physical activity during a typical week (GPAQ), and the fourth part assessed social capital in the family, neighborhood, and school using the Social Capital Questionnaire. In addition to quantitative research methods, a qualitative method in the form of semi-structured face-to-face interviews was also applied. Six participants were selected from each city, making a total of 24 participants, chosen randomly. Six participants were selected from Zagreb, Split, Rijeka, and Osijek, covering gymnasium, vocational technical, and trade educational programs. The combined research methodology provided a deeper analysis of participants' thoughts on the topic of social capital and subjective assessment of well-being during the COVID-19 pandemic. Frequencies were calculated for all categorical variables, while basic statistical parameters (mean, standard deviation, minimum, maximum, median, skewness, and kurtosis) and the Kolmogorov-Smirnov test for normality were calculated for the set of dependent variables related to social capital. Due to issues with the measurement characteristics of Likert-type scale variables, frequency histograms were provided for all the mentioned dependent variables. Differences between groups in the categorical variables of gender and parental education level were analyzed using the Mann-Whitney U test, while differences between groups in the categorical variables of city and educational program were analyzed using the Kruskal-Wallis test. Differences between categorical variables of gender, city, educational program, and parental education level with respect to the categorical variable of health were analyzed using the Pearson chi-square test, and the association among variables was calculated using the contingency coefficient. The significance level observed in all the mentioned tests was corrected using the Bonferroni correction to control for family-wise error rate (FWER). The relationship between the variable HEALTH and the set of family social capital variables, the variable RISK and the set of neighborhood social capital variables, as well as the variable physical activity (PA) and the set of school social capital variables were explored using a sigmoidal logistic regression analysis. Logistic regression analysis was used to calculate the values of the omnibus test, Hosmer and Lemeshow test, Cox and Snell's and Nagelkerke's coefficients of determination, the overall percentage of successful classification of the predictive model compared to the null model, and to calculate the regression equation coefficients and their level of significance. The data were processed using Microsoft Excel (version 2017) and TIBCO Statistica (version 13.5), with the exception of the logistic regression analysis which was processed using the IBM SPSS Statistics program (version 23). The results suggest that parental support and encouragement, as well as shared family activities, have increased the perceived value of subjective health assessment among adolescents. Additionally, the family support experienced by adolescents during the COVID-19 pandemic is positively associated with healthy lifestyles of immediate family members. The results of informal social control suggest that the majority of participants do not perceive their environment as a support for the protection and improvement of mental health during the COVID-19 pandemic. The level of mutual connectedness among students has a positive effect on the overall level of physical activity. Specifically, participation in extracurricular or structured activities within school increases the likelihood of high levels of physical activity in students by 37%. The results showed that during the COVID-19 pandemic, within the domain of family social capital, household chores were distributed unequally with a much higher engagement of girls. A gender difference was also noticed in the greater need for discussing school events among girls. The results of the school social capital indicate that high school students participate the most in extracurricular school activities, while the lowest engagement is observed among students in vocational programs. Additionally, students in the academic program socialize more with their school peers in their free time, while the least social interaction with school peers is observed among students in vocational programs. The neighborhood's social capital suggests that students whose parents have lower levels of education perceive their neighborhood as a safer place compared to the perception of safety among students whose parents have a higher level of education. Regarding the place of residence, there were no statistically significant differences among study participants in terms of social capital variables and subjective health assessment. Differences in self-rated health by gender suggest that the COVID-19 pandemic has had a negative impact on the health of girls. The combined research methodology confirmed the quantitative data and provided a deeper analysis of the participants through the use of semi-structured face-to-face interviews, resulting in a better understanding of their thoughts on social capital and subjective well-being during the COVID-19 pandemic. This study provides an overview of the effects of social capital on adolescent well-being during the COVID-19 pandemic and the underlying mechanisms that explain these effects. The results of this study suggest that strong social ties and reciprocity norms can facilitate crisis management and encourage individuals and communities to adopt adaptive behaviors to protect and enhance adolescent well-being. Given the dynamic nature of the COVID-19 pandemic and the possibility of new variants of the virus, the contribution of this study is enriched with relevant recommendations for preserving and enhancing adolescent well-being.