50 HIV-positive patients (CDC stage III to VI) with oral candidiasis proven by culture and typical clinical findings were treated with fluconazole (50 to 100 mg/day) over a period of eight to 22 days. After completion of treatment, clinical signs of oral candidiasis had disappeared in 45/50 patients. In 10/50 patients, however, increased concentrations of candida both in pharyngeal washes (greater than 10(2) PFU/ml) and throat swabs (greater than 20 colonies/culture) persisted. Four weeks later, clinical candidiasis had reappeared in 22/42 patients and another 14/42 patients without clinical symptoms had pathological concentrations of candida in culture. In no case did treatment with fluconazole itself have to be aborted because of adverse reactions. Most of the patients had multiple concomitant bacterial and/or viral infections requiring comprehensive medication. The side effects observed (nausea, headache, changes in the blood picture, etc.) were due to the concomitant infections and their specific therapy.