Introduction: Neonatal jaundice is one of the most common diseases in neonatal period and 5-10% of all the newborns require phototherapy. Phototherapy has some problems including increasing the duration of hospitalization, costs and mother-child separation so, reducing the duration of phototherapy is important. Our aim was to determine the prophylactic effect of oral agar on serum bilirubin level, clinical jaundice and phototherapy requirement in normal term neonates. Materials & Methods: This double-blind clinical trial included 50 term infants divided into Agar-supplemented group (n=25) and placebo group (n=25). We studied the changes in serum bilirubin values, clinical jaundice and phototherapy requirement at the first, third and fifth days. The results were compared statistically, mainly using analysis of variance with SPSS software. Findings: The birth weight and the weights on the third and fifth days, age, sex, distribution and other demographic variables did not differ between the two groups of infants. Serum bilirubin levels increased in both the groups during the study, but this increase in oral Agar group was significantly lower than that of the placebo group. Further more, clinical jaundice and phototherapy requirement were significantly lower in oral agar group. Discussion & Conclusion: we concluded that agar supplementation in normal term neonates reduces the bilirubin level, clinical jaundice and phototherapy requirement.