Background & Aim: Diet rich in fruits and vegetables is shown to be an important factor in prevention of chronic diseases. Adolescence is a critical period in adopting eating behaviors. Schools are important social environments in adolescents' lives; and are important settings for interventions that aim to improve eating behaviors, including fruit and vegetable intake. This study aimed to assess effectiveness of a school-based intervention based on social cognitive theory on fruit and vegetable (F&V) intake of female adolescents in Tehran.

Methods & Materials: This experimental school based field trial was conducted on 296 female students aged 10-13 years old (157 in the intervention and 139 in the control groups). The intervention included classroom nutrition education on F&V and increasing availability of F&V through school buffet. Psychosocial characteristics of the students were assessed using a questionnaire and F&V intake were measured using 24-hr recall method, at baseline and after three months intervention. Descriptive and inferential statistics were used for data analysis.

Results: After the intervention, vegetable and fruit intake were 0.6 and 0.63 servings higher in the intervention group compared to the controls. Knowledge and self-efficacy scores were significantly higher in the intervention group compared to the control group. Home availability and observational learning scores were significantly decreased in the intervention group.

Conclusion: Through the intervention process, many valuable experiences were gained to be used in future interventions.