Journal of Knowledge and Best Practices in Juvenile Justice & Psychology – The purpose of this study was to determine the influence of responsibility-based physical activity instruction on post-adjudicated youths’ personal and social responsibility perception, physical fitness levels, as well as juvenile correctional officers’ attitudes toward its implementation. An embedded mixed-method design was used. Based on the results, responsibility-based physical activity instruction had no statistically significant effect on youth’s personal and social responsibility perception. However, it positively influenced intervention groups’ personal and social responsibility perception at a rate of 1.19 times per session and did not negatively impact their fitness levels. Furthermore, responsibility-based physical activity may influence juvenile correctional officers’ attitudes toward importance of physical activity for rehabilitation.