In an open phase-III study 103 HIV-positive patients with oral candidiasis were treated with oral fluconazole 100 mg/day for 7-21 days (mean 12.2 +/- 6.1 days). Ninety per cent of the patients presented with the full clinical picture of AIDS, in 83% CD4-lymphocytes were < 100/mm3. Clinical and mycological (smear and mouth rinsing) examinations were performed at the start of therapy, after weeks 1, 2, and 3, and at the end of therapy. The clinical findings showed fluconazole therapy to have achieved cure in 71% of the patients and improvement in 16%. Therapy failed in 13%. Mycological tests revealed elimination in 57% and reduction in colony counts in 23% of patients. Therapy failure according to mycological criteria was observed in 20% of all subjects. Adverse events were recorded for 26% of all patients. A causal connection with study therapy was considered as "unlikely" in 20 cases, "questionable" in 17 cases, and "likely" in three cases. Premature discontinuation of fluconazole therapy was required in seven patients, in three of them because of adverse events due to fluconazole. Even in patients with advanced HIV infection and consequently severe immunodeficiency, fluconazole is an important improvement of the therapeutic spectrum.