Abstract The present study was conducted investigating the psychometric properties of the Behavioral Rating Inventory of Executive Functions - Second Edition (BRIEF-2) in students with externalizing behavior problems. The method was based on correlation research. The statistical population consisted of all male students with behavioral problems between the ages 7 and 12 in East Azarbayejan province who were studying in the academic year 2021-2022. To select the sample, first, students with externalizing behavior problems were identified. Then their parents completed the parent form of Behavioral Rating Inventory of Executive Functions - Second Edition (BRIEF-2) and Coolidge's Neuropsychological Questionnaire (2002). The data was analyzed with 599 people. Cronbach's alpha coefficient, confirmatory factor analysis, and criterion validity were used to analyze the data. The results showed that the behavioral rating inventory of executive functions - second edition (BRIEF-2) has good reliability and validity. Therefore, this scale can be used to evaluate executive functions in students with externalizing behavior problems. Keywords: psychometric properties, behavior rating inventory of executive function, externalizing behavioral problems. Extended Abstract Introduction Externalizing problems such as disruptive behavior, aggression, and breaking rules can be a significant public health issue. These symptoms can have serious consequences for individuals, including dealing with disruptive behavior, feeling insecure or victimized, and incurring economic costs for prevention, treatment, and trials (Constanty et al., 2021). When evaluating children with externalizing behavior problems, it's important to assess their executive functions. Executive functions refer to the cognitive processes that are involved in regulating behavior, such as attention, working memory, and self-control. There is a relationship between executive functions and externalizing behavior problems, which means that how well a child can regulate their behavior is linked to their cognitive abilities. By assessing executive functions, we can better understand the cognitive and behavioral factors that contribute to externalizing behavior problems in children. The Behavior Rating Inventory of Executive Function, Second Edition (BRIEF-2) is currently the most widely used tool for measuring executive functions in children (Pino Muñoz et al., 2021; Parhoon et al., 2022). While BRIEF-2 is a comprehensive tool for assessing executive functions in children, its psychometric features have not been fully examined in children with externalizing behavior problems. The current research aims to answer the question of whether the psychometric characteristics of the BRIEF-2 parent form are appropriate for use in assessing executive functions in students with externalizing behavior problems. Research Question Are the psychometric characteristics of the BRIEF-2 parent form suitable for assessing executive functions in students with externalizing behavior problems? Literature Review Anastasiadis (2023) conducted a study to examine the clinical usefulness of the BRIEF-2 and its associated scales in differentiating between pediatric ADHD presentations and comorbidity. The study used archival data from 211 children between the ages of 5 and 12 who were seen at a university-based ADHD Evaluation Clinic. Ratings from parents and teachers were analyzed separately. The results of the study were consistent with predictions, showing that the Emotional Regulation Index (ERI) was highest in the combined presentation of ADHD. Parhoon et al., (2021) conducted a study to examine the psychometric properties of the Persian version of BRIEF-2 parent-form in children between the ages of six and 12 years. The study used confirmatory factor analysis to analyze the internal structure of the BRIEF-2. The results showed that the model with three indexes (Behavioral, Emotional, and Cognitive) and nine scales (Inhibit, Shift, Self-Monitor, Emotional Control, Initiate, Working Memory, Plan/Organize, Organization of Materials, and Task-Monitor) had a good fit. Jiménez & Lucas-Molina (2019) conducted a study to examine two aspects of BRIEF-2 in a sample of primary school-aged children. The results of the study showed that the confirmatory factor analysis of BRIEF-2 revealed a good fit for the sample. The model with three indexes (Behavioral, Emotional, and Cognitive) and nine scales (Inhibit, Shift, Self-Monitor, Emotional Control, Initiate, Working Memory, Plan/Organize, Organization of Materials, and Task-Monitor) was found to be an appropriate fit for the data. Methodology The current research used a descriptive correlational-normative study method. The statistical population for this study included all male students between the ages of 7 and 12 years old who had behavioral problems and were studying in East Azarbaijan province during the academic year of 2021-2022. The final analysis of the current research included data from 599 questionnaires. The researchers used three different tools to collect data: The Child Behavior Checklist (CBCL), the Behavioral Rating Scale of Executive Functions - Second Edition (BRIEF-2), and the Coolidge Neuropsychological Questionnaire. The researchers used two different software programs, SPSS and Lisrel, to examine the psychometric properties of the BRIEF-2. Results The results of the confirmatory factor analysis of BRIEF-2 in Table 1 and Figure 2 showed that all fit indices, including the square root of the mean error of approximation (RMSEA), were within the desired range. This indicates that the model used in the questionnaire data is an appropriate fit for the data. Table 1. All fit indices of BRIEF-2 confirmatory factor analysis. Fitness indices Values RMSEA 0.098 NFI 0.96 NNFI 0.95 CFI 0.97 GFI 0.94 AGFI 0.89 Fig. 1. Estimation of standardized coefficients Discussion The results of the study showed that the BRIEF-2 has good reliability, as indicated by the examination of Cronbach's alpha coefficients and internal consistency. Additionally, the confirmatory factor analysis confirmed the three-factor model of the scale and its nine components. This suggests that the three-factor structure of the BRIEF-2 is desirable and acceptable in the studied population of school-aged children with externalizing behavioral problems. This finding is in line with the research results of Parhoon et al. (2022), Parhoon et al. (2021), Anastasiadis (2023) and Jiménez & Lucas-Molina (2019). One limitation of this study is that the statistical population was limited to primary school-aged male students with externalizing behavioral problems. Therefore, caution should be taken when generalizing the results to other groups of children. Additionally, the data used in this study was limited to participants from East Azarbaijan province. This means that the results may not be representative of other regions or populations. Besides all limitations, it is suggested that the BRIEF-2 be used as an evaluation and diagnostic tool for assessing executive functions in primary school-aged students with externalizing behavior problems. Conclusion The results of this study suggest that children with high levels of behavioral problems may experience more difficulties with executive functions, which can negatively impact their emotional and motivational abilities. Based on the desirable psychometric properties of the BRIEF-2 and its appropriate criterion validity, it can be used as a tool to evaluate the executive functions of primary school-aged students with externalizing behavior problems. Acknowledgments The researchers express their sincere gratitude and appreciation to all the participants who contributed to the implementation of this research. Without their participation, this study would not have been possible.