Background: After 48 hours of phototherapy, the mean urinary Ca excretion is elevated in numerous neonates in previous studies. Objective: This study aimed to evaluate phototherapy effects on urinary calcium excretion among full term neonates. Patients and methods: This Prospective-cohort study was conducted on 30 term neonates presented in NICU of Pediatrics Department, Zagazig University Hospitals through the period from January 2018 to January 2019. They were exposed to phototherapy. We assessed urinary calcium and sodium excretion post-phototherapy in term neonates. Results: As regards urinary calcium, our results revealed an increment in urinary calcium excretion of about 8.76% post-phototherapy exposure, which was significantly increased after phototherapy. A statistically significant increment in serum sodium after exposure to phototherapy was found. Considering urinary calcium, there was statistically significant increase in urine calcium after phototherapy in female patients aged ≥ 8 days born at gestational age less than 39 week and in those delivered by cesarean section. On the other hand, there was statistically significant decrease in calcium/creatinine ratio after phototherapy in patients delivered by cesarean section only Conclusion: Despite presence of an increment in urinary calcium excretion after phototherapy, no significant difference was found in calcium/creatinine ratio after phototherapy, so no hypercalciuria to be considered, so it cannot cause hypocalcemia.