OBJECTIVE: To investigate nosocomial infection risk factors in acute leukemia in children in order that they are wellrecognized by clinic doctors and the mortality rate associated with them will be decreased. METHODS: A retrospective review of the medical records of 306 children with acute leukemia admitted between January, 1995 and December, 2000 was performed. The data were analyzed with the single factor χ2 test, t test and multifactor logisticregression analysis. RESULTS: The incidence of nosocomial infection was 28.43%(87/306), and consisted mainly of respiratory tract and oral infections. The length of hospitalization, white blood cell count, neutrophil and platelet count were found to be independent risk factors for nosocomial infection. CONCLUSIONS: The length of hospitalization, reduced white blood cell count and neutrophil and platelet count are independent risk factors for nosocomial infection in children with leukecnia.