We evaluated 119 episodes of oropharyngeal candidiasis due to C. albicans to study the patterns of fluconazole susceptibility of the isolates and the characteristics of the patients and to confirm the correlation between fluconazole susceptibility of isolates and therapeutic outcome. Sixty-one isolates were considered susceptible to fluconazole (MICs, < or = 0.5 microg/mL), 33 were intermediate (MICs, 1.0-8.0 microg/mL), and 25 were resistant (MICs, > or = 16.0 microg/mL). Patients infected with resistant strains had significantly lower CD4+ cell counts and a less recent AIDS diagnosis than patients infected with intermediate or susceptible strains. Previous fluconazole therapy and prophylaxis were significantly more frequent for patients infected with resistant and intermediate strains (P < .001). Decreased susceptibility to ketoconazole and itraconazole was observed in resistant and intermediate strains. Fluconazole treatment was ineffective for patients infected with resistant isolates; however, high doses of ketoconazole or itraconazole were successful for nine (81%) of them. Different patterns of fluconazole susceptibility among C. albicans strains are correlated with patients' characteristics and with therapeutic outcomes.