This double-blind, parallel group study compared a 2-week course of terbinafine 250 mg/day with a 4-week course of itraconazole 100 mg/day. A total of 190 patients were enrolled, of whom 129 were evaluable for efficacy. At week 8, 69% of patients treated with terbinafine were classified as effectively treated (mycological cure, and clinical assessment total score < or = 2) vs. 67% in the itraconazole group. At week 16, however, the rating for effective treatment increased to 71% of the terbinafine group, but decreased to 55% of the itraconazole group. This difference was of borderline statistical significance (P = 0.06). The results of this study demonstrate that both drugs can be used safely, and that 2 weeks' treatment with terbinafine 250 mg daily is as effective as 4 weeks' treatment with itraconazole 100 mg daily, but with fewer long-term relapses.