We assessed the safety and efficacy of a two-phase topical treatment with bifonazole-urea ointment in children with onychomycosis. Twenty-five children younger than 16 years old with proved onychomycosis were included in the study. Bifonazole-urea ointment was administered under occlusion until the nontraumatic removal of the nail was achieved. Bifonazole cream was then applied for 4 weeks and a follow-up visit 4 weeks after cessation of medication was scheduled. During the study, periodic clinical and mycologic evaluations were carried out. Of the 25 patients included, 17 were cured (68%), 6 improved, and 2 failed treatment. The main etiologic agent isolated was Trichophyton rubrum (92%). Two patients had minor side effects, both during the occlusive phase, one each with mild pain and a probable dermatitis from the adhesive strips. Treatment was not discontinued in both of these cases. We concluded that a two-phase treatment with bifonazole-urea is effective and safe, and represents a new therapeutic choice for onychomycosis in children.