Background: One of the widespread problems of oral health is bruxism and is defined as a parafunctional habit with involuntary grinding and gnashing of the teeth occurring during sleep. However, bruxism is connected to anxiety and stress, but the published literature on bruxism among prison inmates is scanty. Objective: The objective of the study was to determine the prevalence of active sleep bruxism and its impact on oral health-related quality of life (OHRQoL) among inmates in Central Penal Institution, Mysore. Materials and Methods: The study was cross sectional and conducted among eligible male inmates at Central Penal Institution, Mysore. The information on active sleep bruxism and OHRQoL was collected using a predesigned structured questionnaire by means of personal interview by a trained investigator. The active sleep bruxism was assessed using the criteria of American Academy of Sleep Medicine and OHRQoL through modified oral health impact profile (OHIP-14). The data analysis was done using descriptive statistics, Chi-square test, t-test, analysis of variance, and linear regression model. Results: A total of 212 male inmates aged between 18 and 80 years were considered for the study. The prevalence of active sleep bruxism among the study population was 31.6%. The mean OHIP-14 score was significantly higher (P < 0.001) among the inmates having active sleep bruxism (38.52 ± 12.8) suggesting a high oral health impact as compared to inmates without this disorder (31.67 ± 12). Conclusion: The prevalence of active sleep bruxism was higher among the inmates of penal institution as compared to the general population. The active sleep bruxism had a negative impact on OHRQoL.