Background Obesity is now a global epidemic problem. Increased prevalence of obesity is associated with increased sedentary beh avior and low physical activity. Objective To assess the physical activity patterns of adolescents aged 10-15 years and to compare mean energy output, intensity of physical activity, duration of moderate-vigorously intensity of physical activity, and length of screen time in obese and non-obese adolescents. Methods This cross-sectional study was conducted on 7th and 3th grade students aged 12-15 years at 216 junior high schools in West Jakarta. Physical activity was assessed using th e Bouchard diary for 2 school days and 1 holiday. Results There was no significant differen ce in mean energy output between th e obese and non-obese adolescent s. Th e median intensity of physical activity of obese adolescents was lower than that of non-obese adolescents [1.5 (range 0.8 to 1.8) vs. 2 (range 1.6 to 2.8) METs, respectively; P <0.00 1] . The mean duration of moderate-vigorous intensity of physical activity in obese adolescents was shorter than that of non-obese adolescents [19.3 (SD 6.9) vs. 26.4 (SD3.4) minutes, respectively; P= 0.000]. Median length of screen time was longer for obese adolescents than for non -obese adolescents [2.8 (range 1 to 6.6) vs. 1.8 (range 0.3 to 6.1) hours, respectively; P < 0.001]. There was no adolescent who met the recommended physical activity intensity and duration criteria. Conclusion Physical activity varies among adolescents aged 10- 15 years. Obese adolescents have signific antly less physical activity duration and intensity than n on-obese adolescents, but significantly longer screen time. All adolescents' physical activity is less than the recommended intensity and duration.