In an open, multicentre evaluation carried out in Brazil, Canada and South Africa we have demonstrated that fluconazole 8 mg kg-1 once weekly is effective in tinea capitis caused by Trichophyton and Microsporum species. There were 61 children, aged (mean +/- SE) 5.0 +/- 0.3 years; weight (mean +/- 5.6) 20.0 +/- 0.9 kg; 41 males, 20 females; one Asian, 57 Black, one Caucasian and two Hispanic. The organisms were Trichophyton violaceum (33 patients), T. tonsurans (11) and Microsporum canis (17). The extent of tinea capitis at pretherapy was: mild (18 patients), moderate (30) and severe (13). Patients with tinea capitis due to Trichophyton species were initially treated for 8 weeks with an extra 4 weeks of fluconazole if clinically indicated. All 44 patients with tinea capitis due to Trichophyton species were completely cured (clinically and mycologically) when evaluated 8 weeks after completion of active treatment, following 8 weeks of once weekly dosing in 35 patients and 12 weeks of once weekly dosing in nine patients. In Microsporum canis tinea capitis, an extra 4 weeks was administered at week 12 in patients where it was clinically indicated at the time. Sixteen of 17 patients with M. canis tinea capitis were completely cured (clinically and mycologically) when evaluated 8 weeks following the end of treatment when given for 8, 12 and 16 weeks in 12, one and three patients, respectively. Overall, complete cure (clinical and mycological) occurred in 60 of 61 patients at follow-up 8 weeks from the end of therapy. The duration of once weekly fluconazole in the 60 patients was 8 weeks (47 patients), 12 weeks (10 patients) and 16 weeks (three patients), respectively. Clinical adverse effects consisted of a mild, reversible gastrointestinal complaint in three (4.9%) of 61 children. A laboratory abnormality with elevated liver function tests was observed in one (5.9%) of 17 patients; this was asymptomatic, and reversible. No patient discontinued therapy. The data suggest that once weekly fluconazole dosing is effective, safe and associated with high compliance when used to treat tinea capitis.