To evaluate the mechanism and risk factor associated with the nosocomial acquisition of Candida albicans, a 3-month prospective study was conducted on non-neutropenic patients in three distinct intensive care units in distinct hospitals. A total of 43 samples from 19 patients has been typed by multilocus enzyme electrophoresis (MEE). Samples (24) from the deep pharynx of hospital staff members were also cultured and typed. Thirteen of the 19 enzyme loci studied were polymorphic. The 52 electrophoretic types were assigned to 67 isolates, each type was represented by one to five isolates; this proved the great diversity of the isolates. It appeared that most patients were colonized or infected with different C. albicans strains. This study pointed out a possible cross-infection between patients and hospital staff and between healthy members of the hospital staff, and also showed the successive stages of infection by different electrophoretic types. Intubation and respiratory equipment as surgery intervention were possible sources of observed infections.