The purpose of this article is to review the pharmacologic properties of two newer agents, itraconazole and terbinafine, and to assess their clinical efficacy in onychomycosis. Both drugs are effective in treating infections caused by dermatophytes. Itraconazole appears to be more efficacious in infections caused by Candida species. The improved effectiveness of these agents is probably related to their rapid penetration into the nails and prolonged bioavailability at the site of infection.