Background: Previous studies have revealed that sedentary behavior, including quantitative and qualitative parameters, was associated with health-related quality of life (HRQOL) in patients on chronic hemodialysis., Objective: The present study examined the relationships between various parameters of prolonged sedentary bouts on non-hemodialysis days and HRQOL in patients on chronic hemodialysis., Methods: A total of 110 patients (47.2%) on chronic hemodialysis (64 men and 46 women, aged 71.4 ± 11.2 years) among 233 patients, who were outpatients at a hospital in Hiroshima prefecture, Japan, were enrolled in this cross-sectional study. Prolonged sedentary bouts were evaluated using a tri-accelerometer, i.e., sedentary behavior (minutes), median sedentary bouts (minutes), maximum sedentary bouts (minutes), sedentary bouts (bouts and minutes/bout), and prolonged sedentary bouts (≥5, ≥10, ≥30, and ≥60 minutes; bouts and minutes/bout). HRQOL was assessed using EuroQol 5-Dimension (EQ-5D)., Results: The EQ-5D score was 0.755 ± 0.216. All prolonged sedentary parameters, except for sedentary bouts (bouts), correlated with HRQOL, and higher correlation coefficients were observed between sedentary behavior (minutes) and HRQOL (r = -0.416) and between maximum sedentary bouts (minutes) and HRQOL (r = -0.436) than between other parameters. These parameters were also identified as factors affecting HRQOL, even after adjustments for confounding factors., Conclusion: In summary, sedentary behavior (minutes) and maximum sedentary bouts (minutes) on non-hemodialysis days, which may be representative of quantitative parameters for sedentary behavior, correlated with HRQOL in patients on chronic hemodialysis., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. The Ethical Committee of Innoshima General Hospital issued approval Approval number (date): H25-2-27 (Feb 27, 2013), H26-1-23 (Jan 23, 2014), H26-12-16 (Dec 16, 2014), H27-12-25 (Dec 25, 2015), H28-12-9 (Dec 9, 2016), H29-12-4 (Dec 4, 2017), H30-11-1 (Nov 11, 2018), H31-2-25 (Feb 25, 2019), R1-12-23 (Dec 23, 2019), R2-11-9 (Nov 9, 2020), R3-11-10 (Nov 10, 2021), R6-4-22 (Apr 22, 2024). Ethical approval was obtained from the Ethical Committee of Innoshima General Hospital, Onomichi, Japan. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: This research was supported in part by research grants from the Ministry of Education, Culture, Sports, Science and Technology, Japan (JSPS KAKENHI grant nos. JP 17K01851, 20K11557, and 24K13508). Financial relationships: Nobuyuki Miyatake declare(s) a grant from Ministry of Health, Labour and Welfare, Japan. This research was supported in part by research grants from the Ministry of Education, Culture, Sports, Science and Technology, Japan (JSPS KAKENHI grant nos. JP 17K01851, 20K11557, and 24K13508). Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Sugahara et al.)