A patient with AIDS developed oropharyngeal candidiasis. Candida albicans and C. glabrata were isolated from the patient and found to be resistant to fluconazole and itraconazole in vitro. Voriconazole therapy was initiated, but discontinued when the C. albicans strain isolated from the patient was found to be resistant to it. The patient failed to respond to subsequent therapy with a combination of amphotericin B and 5-flucytosine. Therapy with caspofungin was then initiated (70 mg loading dose, followed by 50 mg/day). The patient responded favourably to caspofungin, with complete resolution of signs and symptoms.