Unconjugated hyperbilirubinemia is one of the most common problem that can occur in the newborn. This prospective cross sectional study was conducted in NIMS Medical College, Jaipur, Rajasthan, India. during period from 1^st feb 2015 to 31^st july 2016. The study group included 200 neonates (155term and 45 preterm). fulfilling the criteria of jaundice and requiring phototherapy. Measurement of serum calcium level was done before and after 48 hours of initiation of phototherapy in these two groups. Out of 200 neonates, 86(43%) developed hypocalcemia after 48 hours of phototherapy. Out of 45 preterm  24 (53.33%)   and 155 term  62 (40%)   neonates (p=0.156) developed hypocalcemia. Mean±SD serum calcium levels were significantly lowered in both preterm (p<0.001) and term neonates (p<0.001), while no significant difference were found between these two groups(p<0.247 ). Of the 62 term neonates who had hypocalcemia, 13(20.96%) were symptomatic and of the 24 preterm neonates who had hypocalcemia, 12(50%) were symptomatic i.e.jitteriness, irritability/excitability,letharginess etc.

Conclusion: Phototherapy induced hypocalcemia is a significant problem and there is a need for close monitoring of calcium levels in neonates subjected to phototherapy. Provision of calcium supplementation as prophylaxis and head covering may be considered in neonates subjected to phototherapy.