Abstract INTRODUCTION: Many people do not have sufficient knowledge about cardiovascular risk factors in Iran. We used a school-based educational intervention program to promote the health knowledge in all participating families. methods: A total of 1100 fifth-grade school children and their parents were invited; 603 families were included in the study. The children attended a single session and were supplied with family information packages. Pre- and post-test questionnaires were completed by these families before and after the session. results: There was a significant increase in the overall cardiovascular risk factor knowledge of families (P<0.001). The parents of boys achieved a greater level of health knowledge in comparison to the parents of girls (P<0.005). CONCLUSIONS: This school-based educational intervention was effective in improving cardiovascular risk factor knowledge of families. Similar programs with more comprehensive methodology could be more effective in promoting healthy behaviors. Keywords: Education, Cardiovascular Disease, Risk Factor, School-based Interventions.