The efficacy and safety of two dos-ages of itraconazole in the treatment of tinea corporis or cruris were compared in a multicentre, randomized, double-blind, parallel-group trial. Fifty-four patients received itraconazole 100 mg daily for 2 weeks and 60 received itraconazole 200 mg daily for 1 week. After a 6-week follow-up period, mycological cure was achieved in 70% of patients in the 100 mg/2 weeks group and in 60% of those in the 200 mg/1 week group (not significantly equivalent); in the worst-case and intention-to-treat analyses, mycological cure rates (45-49%) were borderline equivalent at the end of follow-up. Clinical response was seen in 80% of evaluable patients in the 100 mg/2 weeks group and in 73% in the 200 mg/1 week group at the end of follow-up (borderline equivalent). Similar results were found in the intention-to-treat analysis. The tolerability ratings for the two regimens were significantly equivalent. Thirteen patients (24%) in the 100 mg/2 weeks group but only nine (15%) in the 200 mg/1 week group reported adverse events during treatment. Two patients in the 200 mg/1 week group stopped treatment because of adverse events. No clinically significant changes were seen in laboratory parameters in either treatment group. This trial showed that itraconazole 200 mg for 1 week is similarly effective, equally well tolerated and at least as safe as the established regimen of itraconazole 100 mg for 2 weeks in the treatment of tinea corporis or cruris.