Objective  To investigate long-term effect of neonatal hyperbilirubinemia. Methods  Intelligence, nervous system and physical growth in 63 children at 1-8.5 years of age who had neonatal indirect hyperbilirubinemia were analyzed. Results  19 cases(30.2%) had intelligence retardation to different extent, 7 cases(11.1%) had neurological abnormalities, and 1 case(1.6%) had abnormal physical growth. There was no significant correlation between the long-term abnormal outcome and the serum bilirubin level. In about half of the cases who experienced unfavourable outcome, the serum bilirubin level was under 340?μmol·L    -1. There were significant differences of frequency of abnormal intelligence and nervous system between the hemolytic and the non-hemolytic groups, which suggested that not only severe, but also slight and moderate hyperbilirubinemia, resulting from both hemolytic and non-hemolytic disease, exerted permanent neurotoxicity to new born infant resulting in abnormal psycho-neurological development.Conclusions  Serum bilirubin level dose not precisely predict long-term  outcome. Neonatal indirect hyperbilirubinemia, especially due to hemolytic disease should be prevented and treated more aggressively to minimize psycho-neurological sequellae.