Objective: To assess the effectiveness of an educational intervention based on social cognitive theory on increasing consumption of fruit and vegetable among Grade 4 students. Methods: The randomised study was conducted in Isfahan, Iran, during 2011 and comprised 138 students, who were randomly divided into intervention and control groups. Data was collected at the beginning and three months after the intervention. A self-administered questionnaire based on constructs of social cognitive theory and food consumption was used. Theory-based nutrition education was imparted on the intervention group. Data was analysed using SPSS 15 and appropriate statistical tests. Results: The intervention group had 68 (49.27%) subjects, while there were 70 (50.72%) controls. After the intervention, mean scores of behavioural capability (p