Itraconazole, the first orally active triazole antifungal agent, was tested in 185 cases of acute or chronic (recurrent) dermatophytosis. The skin infections were divided into two major diagnostic groups: tinea corporis/tinea cruris (91 cases) and tinea pedis/tinea manuum (94 cases). Each patient was randomly assigned to a regimen of 50 or 100 mg of itraconazole daily. Of the cases of tinea corporis and/or tinea cruris, 94% responded to 50 mg of itraconazole daily and 96% to 100 mg daily. The effects of therapy were evident earlier when 100 mg daily was given. Of the cases of tinea pedis and/or tinea manuum, 80% responded to 50 mg of itraconazole daily and 94% to 100 mg. Again, improvement was seen sooner with the lOO-mg regimen. Only five patients (2.9%) reported minor adverse reactions. Hematologic and blood-biochemical parameters were monitored before treatment and at biweekly intervals thereafter in 37 patients; no significant abnormalities were observed. Thus, either 50 or 100 mg of itraconazole daily constitutes effective treatment for dermatophytoses. Since the larger dosage induces a faster response, it should be evaluated further.