We studied 70 intensive care unit patients to determine the incidence of nosocomial candiduria associated with indwelling urinary catheters and to assess microbiological characteristics of the yeasts. The yeasts were isolated, 13 of 17 in urine cultures and 4 of 17 in blood cultures, and colonization had occurred 3 days after the insertion of indwelling urinary catheters. For four strains the MICs of the antifungal drugs were high.