Increases in the prevalence of yeast species other than C. albicans as agents of disseminated mycoses in immunosuppressed patients and of fluconazole-resistant C. albicans isolates from patients infected with HIV indicate changes in the epidemiology of Candida infections. The precise reasons for alterations in prevalence of various agents are difficult to pinpoint but changes in the types of host populations at risk of Candida infection and selection of resistant yeast populations by widescale usage of certain antifungal agents seem to be factors involved in the process. Greater attention to speciation of clinical yeasts and standardized susceptibility test methods are needed for future epidemiological surveillance.