Objectives: To identify the causes of neonatal jaundice at National Institute of Child Health, Karachi Study design: Cross-sectional study. Setting: Neonatal Intensive Care Unit of National Institute of Child Health, Karachi. Duration with dates: One year from 27 th September, 2006 to 26 th September, 2007. Subjects and methods: Hundred cases of neonatal jaundice included in this study. Procedure was explained to the parents and informed consent was taken. Neonates with congenital anomalies of central nervous system and meningitis were excluded. Results: Total 100 cases of neonatal jaundice, out of them 62 were male and 38 females. Age range was 1 - 15 days. 56 were in range of 1 - 5 days. Prematurity was seen in 39. Fifty five neonates were of low birth weight. Hypothermia was seen in 44 neonates. Home delivery was conducted in 60 cases. Haemolysis was seen in 30 and Sepsis in 52 respectively. Mean (+ SD) for bilirubin was 27.4 with range (14.5 - 48.4mg/dl). Conclusion: neonatal jaundice is common condition. Majority of patients delivered at home and presented in late stage. Infection, prematurity and low birth weight, sepsis and hemolysis were common causes documented in this study. This reflects poor antenatal care, lack of parental awareness and falls belief that jaundice will resolve on own, exposure to sunlight or visiting to faith healers.