ABSTRACT Objective: to analyze the factors associated with physical activity levels in adolescents. Method: cross-sectional, quantitative study, conducted with adolescents enrolled in two educational institutions in a capital of the midwest region of Brazil. Data collection occurred from April to October 2021, through a self-administered questionnaire composed of validated scales. The association between the variables was verified by logistic regression. Results: 219 adolescents participated in the study, with a mean age of 15.7 years, more than half were girls (52.5%) from medium economic class (51.1%); 55.3% were very active/active; 39.3% had low self-esteem; 17.8% were at risk for developing an eating disorder; 12.3% at risk for severe anxiety symptoms; and 13.3% at risk for moderate depression symptoms. The factors associated with the level of physical activity were self-esteem and risk for depression. Conclusion: Early screening of adolescents with low self-esteem and risk for symptoms of depression is proposed as an initial strategy to direct actions that encourage the practice of physical activity.