A multicentre, randomized, double-blind, parallel-group trial was conducted to compare the efficacy and safety of two dosages of itraconazole in the treatment of tinea pedis or manuum. Of the 135 patients recruited, 66 received itraconazole 400 mg daily for 1 week and 69 received itraconazole 100 mg daily for 4 weeks. In the evaluable patients observed-case analysis, mycological cure was seen in 63% of patients in the 400 mg/1 week group and in 75% in the 100 mg/4 weeks group at the end of a 6-week follow-up period (not significantly equivalent). In the evaluable patients worst-case analysis and the intention-to-treat analysis, mycological cure rates in the two groups were borderline significantly equivalent at the end of follow-up (range 51-57%). Clinical response was seen in 81% of evaluable patients in the 400 mg/1 week group and in 75% in the 100 mg/4 weeks group at the end of follow-up; equivalence testing showed the 400 mg/1 week regimen to be at least equivalent to the 100 mg/4 week regimen. Similar results were found in the intention-to-treat analysis, and tolerability ratings for the two treatment regimens were significantly equivalent. This trial has shown that itraconazole 400 mg/1 week and itraconazole 100 mg/4 weeks are both effective regimens for the treatment of tinea pedis or manuum. The two treatment schedules were equally well tolerated and safe.