Ajoene, an organosulfur compound originally isolated from garlic, has been shown to be effective in short-term treatment of tinea pedis. We compare the safety and effectiveness of twice-daily topical application during 1 week of 0.6% and 1% ajoene and 1% terbinafine in the treatment of tinea pedis. Seventy soldiers from the Venezuelan Armed Forces, with clinical and mycologic diagnosis of tinea pedis, were included in this study. However, only 47 were available for final evaluation. The patients were randomly distributed into 3 treatment groups: 0.6% ajoene, 1% ajoene, and 1% terbinafine. Clinical follow-up shows a rapid decline in the signs and symptoms in all groups. Efficacy of the treatments, measured as mycologic cure, 60 days after the end of the therapy was 72% for 0.6% ajoene, 100% for 1% ajoene, and 94% for 1% terbinafine. This represents the first demonstration of the therapeutic application of an inhibitor of phospholipid biosynthesis in human dermatophytosis.