This study was performed in order to evaluate the risk factors for nosocomial urinary tract infection and the frequencies of organisms isolated, and to provide the epidemiologic and basic data of hospital acquired urinary tract infection in intensive care unit. A prospective analysis was performed with 1,235 urine samples following urinary bladder catheterization in 569 patients, who had no evidence of UTI at the time of catheter insertion, admitted to intensive care unit in Pusan P hospital between June 1997 and May 1998. To identify risk factors for UTI, clinical characteristics of infected patients were analyzed. We analyzed these data by percentage, chi-square and odd ratio. Obtained results were as follows: A total of 569 patients (male 341 and female 228) were an average age of 50.8 years and catheterization of 8.04 days. Incidence of UTI was 16.1% (199/1,235) and The risk factors of UTI were duration of catheterization over 7 days, no use of systemic antibiotics, summer and female, and During the first 7 days these risk factors were no use of systemic antibiotics, summer, place of first catheter insertion (ICU) and type of intensive care unit (NSICU). A total of 220 the isolated strains were Gram negative rod 83 (37.7%), yeast like fungi 74 (33.6%) and Gram positive cocci 63 (28.6%). The common organisms isolated were Enterococcus faecalis 23 (10.5%), Serratia marcescens 19 (8.6%), Pseudomonu spp.17 (7.7%), E. ooh 16 (7.3%), Staphylococcus epidemidis 11 (5.0%) mdklebsiellapneumoniae 8 (3.6%). Therefore, in these results 199 of 569 (35%) patients in ICU with indwelling urinary catheter developed UTI. The risk factors for UTI are prolonged duration of catheterization, no use of systemic antibiotics, summer, and female.