Introduction: During adolescence, the practice of physical activity (PA) decreases, as well as the consumption of healthy foods, which could be attributed to the socioeconomic status. Objective: Associating socioeconomic status with quality of food and level of PA in adolescents. Methods: Descriptive - correlational study, which evaluated 158 students between 14-15 years old belonging to municipal and private establishments in Talca, Chile through a non-probabilistic sampling for convenience. The PA Physical Activity Questionnaire for Adolescents (PAQ-A) questionnaire was applied, the quality of food was assessed with the global food quality index and the Adimark survey to assess the socioeconomic status. Results: 41.2% of the participants reported an "unhealthy" diet, 51.2% had a PA level below average and 44.1% categorized themselves with a "medium" socioeconomic status. On the other hand, a statistically significant association was observed between socioeconomic status and food quality (p=0.01), but no significant association was found between socioeconomic status and PA level (p=0.89). Conclusions: There is an association between the quality of diet of adolescents with the socioeconomic status of the home where they reside, however this was not associated with the level of PA. Considering the high prevalence of overweight and obesity in adolescents, it is necessary to promote the practice of PA and a good quality diet in all socioeconomic status, but particularly in the most vulnerable levels. © 2024 Federacion Espanola de Docentes de Educacion Fisica. All rights reserved.