Background: Tinea capitis is prevalent in children. Although widely used as the drug of choice, the response to griseofulvin may be incomplete and an extended duration of therapy is often required. The response to newer antifungals has not been methodically evaluated in children with Trichophyton tonsurans infection. Objective: Our purpose was to determine the efficacy of itraconazole in children with tinea capitis caused by T. tonsurans. Methods: Pediatric patients with culture proven tinea capitis were enrolled from a hospital-based primary care clinic between January and December of 1996. Patients were treated with itraconazole 100 mg/day and a selenium sulfide–containing shampoo for 4 weeks. Children were evaluated mycologically and clinically every 2 weeks for 2 months. Patients were considered successfully treated if they were culture negative and clinically improved at the end of the study period. Children who remained culture positive or who were clinically not improved at 2 months were classified as treatment failures and re-treated. Results: Twenty-five patients completed the study, and 10 (40%) were successfully treated. Fifteen children required re-treatment: 14 remained culture positive at week 8, and one was mycologically negative but clinically worse. Conclusion: Itraconazole at a dose of 100 mg/day for 4 weeks may be effective in less than half of children with T. tonsurans tinea capitis. (J Am Acad Dermatol 1998;38:443-6.)