The aim of the present study is to test a hypothesis assuming that phototherapy might have an effect on oxidant/antioxidant status in term and late-preterm neonates with unconjugated hyperbilirubinemia.

Inclusion Criteria:

• Term and late-preterm neonates (≥35weeks) according to the guidelines of the American Academy of Pediatrics (2004) which stated that gestational ages of newborns were determined according to the first day of the mother's last menstrual period (by the mother's statement) and were additionally confirmed by the Ballard scoring system (Ballard et al., 1991) and antenatal ultrasonographic estimation or obstetric records if present.
• Clinical significant indirect hyperbilirubinemia requiring phototherapy in the first week of life.
• Normal blood counts and peripheral blood smears
• Normal reticulocytic count.
• Breast fed newborn.

Exclusion Criteria:

• Those in whom the total serum bilirubin (TSB) level rose by more than 5 mg/dl per day or was higher than 20 mg/dl within the first 24 hours after birth were excluded from the study.
• Infant of diabetic mothers.
• Maternal eclampsia-preeclampsia.
• Birth asphyxia
• Sepsis
• congenital anomalies.
• Direct Coombs'test positive
• Pathological causes of hyperbilirubinemia.
• Enclosed hemorrhage.
• Hemolytic type of hyperbilirubinemia due to blood group or Rh incompatibility.