BACKGROUND: Health-promoting behaviors are important to prevent diseases and prolong life in the population. People develop these behaviors throughout life. However, better benefits for health are obtained with an early development. AIM: To determine the prevalence of health-promoting behaviors among early adolescents and its associated factors. MATERIAL AND METHODS: Cross-sectional survey performed in 1,465 students of high, medium and low socio-economic status, attending fifth to eighth grades of schools located in a small Chilean city. Participants answered a questionnaire that gathered information about frequency of health-promoting behaviors such as health responsibility and nutrition, physical exercise and stress management, life appreciation, social support and different personal, school and familial factors. RESULTS: A higher frequency of health-promoting behaviors was associated with better academic achievement, better school commitment, and higher perception of school membership. It also was associated with a better perception of health status and a higher conformity with physical appearance. CONCLUSIONS: Health promoting behaviors in these children are related to a better academic achievement and a higher integration with school environment.