Abstract Objective The objective was to identify risk factors for nephrocalcinosis in very low birth weight (VLBW) infants. Methods Prospective study has done between 2014 and 2017. The study included 81 VLBW infants in the neonatal intensive care unit (NICU). Renal ultrasonography was performed at four weeks and 3 months. Baseline characteristics, complications and medication during NICU admission were collected. 25-(OH)-vitamin D, calcium, phosphorous, alkaline phosphatase, urine calcium to creatinine ratio were serially measured. Results The incidence of nephrocalcinosis was 16.9%. On univariate analysis, gestational age, lower birth weight, maternal pregnancy-induced hypertension, neonatal sepsis, and frequency of vancomycin and caffeine citrate treatment were significantly associated with nephrocalcinosis. In addition, preterm infants with nephrocalcinosis had lower cord blood 25-(OH)-vitamin D and serum calcium levels and higher serum alkaline phosphatase levels at 2 weeks of life. Multivariate analysis showed that gestational age ( P =0.042), birth weight ( P =0.019), sepsis ( P =0.046), small for gestational age ( P =0.015), and maternal pregnancy-induced hypertension ( P =0.024) were significant risk factors for nephrocalcinosis. Conclusion This study suggests that neonatal sepsis and maternal pregnancy-induced hypertension, in addition to gestational age and birth weight are important perinatal risk factors for nephrocalcinosis.