Background. Icterus tends to be one of the most prevalent causes of neonatal hospitalization. The present study aimed to evaluate the effects of the different doses of ursodeoxycholic acid (UDCA) on neonatal jaundice. Method. In this study, 120 newborns who were hospitalized for phototherapy were randomly assigned. Group A received phototherapy and UDCA 5 mg/kg/dose every 12 hours orally, group B patients were treated with phototherapy and UDCA 7.5 mg/kg/dose every 12 hours orally. Group C received phototherapy with a placebo. All patients were evaluated for bilirubin levels, the duration of phototherapy, and the length of hospital stay.Results. The mean bilirubin level at hospital admission was 19.88 ± 2.33 mg/dl in group A, 19.33 ± 2.51 mg/dl in group B, and 19.76 ± 2.64 mg/dl in group C (p= 0.58). The groups receiving phototherapy with UDCA showed a significant decrease in the bilirubin level. Bilirubin level decreased to 10.04 ± 1.11mg/dl in group A, 8.82 ± 1.11 mg/dl in group B, and 12.04 ± 2.05 mg/dl in group C (p= 0.000). Furthermore, the mean duration of phototherapy, as well as the average length of hospital stay, were significantly lower in group B as compared to the other groups (p= 0.000).Conclusion. The findings of this study indicated that the administration of UDCA in addition to phototherapy could effectively decrease the length of hospital stay and bilirubin levels in neonatal hyperbilirubinemia. However, further studies with a larger sample size are required before one can recommend the routine use of UDCA for the treatment of neonatal jaundice.