Objective: To evaluate the effect of an internet intervention to improve cognitive health factors ("Lifestyle perception, self-efficacy and health status in adolescents"). Methodology: The pre experimental test-retest design was done with a sample of 250 adolescents. The intervention was named "S@lud y Más". It was programmed to be completed in eight weeks. The contents were offered in six topics (Nutrition, physical activity, stress management, health responsibility, spiritual growth and interpersonal relationships). Results: It was differenced regarding to the first and second measures in the lifestyle indicators, perception of health status and self-efficacy increased significantly at the end of the intervention (p<.05). Conclusion: The intervention by internet was effective to improve cognitive factors in the adolescents.