BACKGROUND & AIM: Hyperhomocysteimemia is a cardiovascular risk factor even among children. Supplementation of oral folic acid may reduce homocysteine levels to normal. However, data is limited at this point for healthy children and adolescents.METHODS: Five hundre and twenty four children participated in the study; Twenty six of them were found to be hyperho mocysteinemic(>95(th) percentile for age). Twenty of them received 5 mg of folic acid twice per week for two consecutive months while the other six received a diet rich in dietary folate.RESULTS: Serum homocysteine levels were statistically significantly decreased from 13.1 (10-24.2 micromol/L ) to 7.7 (4.9- 15.2 micromol/L), p<0.001. Serum folate levels were significantly rose from 4.3 (3-20 ng/mL) to 16.8 (7-20 ng/mL), p<0.001. On the contrary, no important changes were observed in the above parameters in children to whom a diet rich in folic acid was recommended. Homocysteine levels were found to be positively associated with age (r=0.314, p<0.001), BMI (r=0.192, p<0.001), WC (r = 0.215, p<0.001), simple sugars (r= 0.182, p<0.001 ) and negatively associated with folic acid (r = -0.331, p<0.001), vitamin B12 (r = -0.214, p<0.001) and dietary folic acid (r= -0.228, p=0.003).CONCLUSIONS: Oral folic acid 5 mg twice per week may efficiently reduce serum homocysteine levels and increase serum folic acid levels in healthy children with increased homocysteine levels (>95(th) percentile for age). Hyperhomocysteinemia in childhood may be a predictive factor of cardiovascular disease. In addition, these results may offer more help to health practioners in order to establish more prospective studies to elucidate the relationship between homocysteine, folic acid and heart disease in children.