Thirty patients (18 males and 12 females) with dermatophytoses were treated with itraconazole. Twenty-eight patients received 100 mg per day for 14 days, and two patients, one with tinea pedis and one with tinea manuum, were treated for 28 days. Thirty patients (11 males and 19 females) with pityriasis versicolor were treated with 200 mg of itraconazole. for five days. Half of the patients received the 200 mg in one dose, and the other half received 100 mg twice a day. Twenty-nine of the 30 patients with dermatophytoses were clinically and mycologically cured, and one patient was improved. All 30 patients with pityriasis versicolor experienced complete clinical and mycologic cure; no difference was noted between the two groups. Ten of the 60 patients treated reported adverse reactions to therapy. The primary adverse effects were nausea and epigastric pain; one patient had diarrhea. There were no alterations in the patients' blood biochemical values. These results suggest that itraconazole is safe and effective for the treatment of dermatomycoses.