A quasi-experimental, longitudinal study was conducted to test the effectiveness over a 1-year period of a cardiovascular risk reduction program for school-age children. The effectiveness of the program was measured with the children's knowledge of physiology of the heart and cardiovascular risk factors, their health habits, and their physical measurements. Ninety-eight children between the ages of 9 and 12 years participated in the study. The experimental group received a series of five 40-minute sessions on physiology of the heart, smoking, hypertension, diet, and physical activity. Short-term effectiveness of the program was found for the children's knowledge of physiology of the heart and smoking. Long-term effectiveness was found for running activity.