Candida species are by far the most common agents of mucosal fungal infection in man. While Candida albicans is the most notorious pathogen in this group, non-albicans species such as Candida krusei are gradually emerging as pathogens of concern, especially in compromised hosts. It is thought that the wide use of the newer triazole drug, fluconazole, in HIV-infected individuals is contributing to this phenomenon. Studies in both humans and animals have now demonstrated prophylactic and therapeutic failure of fluconazole against C. krusei due to increasing resistance of the organism to this azole. Thus, the indiscriminate use of fluconazole, a drug with relatively minimal toxicity and excellent pharmacokinetics, may lead to the development of widespread resistance to this azole among Candida species.