Background: Physical activity is a part of a healthy lifestyle, however sedentary habits are currently prevalent among adolescents which impacts rates of overweight and obesity in this group. This study aims to describe the relationship of physical activity with the use of active transportation to school (ATS) and its relationship with body composition in adolescents. Materials and Methods: Information about physical activity, sedentary behavior and active transportation were collected through two survey instruments, one completed by a responsible parent/guardian and other by the adolescent. Body composition was assessed by dual-energy x-ray absorptiometry (DXA). Excess body fat was defined as ≥ 25% in male and ≥ 30% among female adolescents. Less than 60 minutes of moderate to vigorous daily physical activity defined one as sedentary and greater than 2 hours of screen time per day was defined as excessive. Results: The prevalence of excess body fat was 46.5%. Only 24.7% of the sample performed recommended amounts of physical activity and 92.3% engaged in excess screen time. Approximately one-fifth of our sample (19.2%) used ATS. The main barriers to active transport were traffic, distance and safety. Those that used ATS had lower body fat and fewer hours of sedentary behavior.