Background: Griseofulvin has been used for many years in the treatment of tinea capitis. Increase in resistance to this medication has led to a search for new therapeutic alternatives. Objective: Our purpose was to evaluate the therapeutic efficacy of terbinafine in comparison with griseofulvin in the treatment of tinea capitis. Methods: We performed a double-blind, randomized, prospective evaluation of 50 patients with a clinical and mycologic diagnosis of tinea capitis. One group received 4 weeks of terbinafine followed by 4 weeks of placebo. The other group received 8 weeks of griseofulvin. We evaluated 5 clinical parameters. Mycologic examinations were performed at baseline and at the end of weeks 8 and 12. Results: Patients' ages ranged from 1 to 14 years. Fifty-four percent were girls and 46% were boys. Mycologic examinations disclosed Trichophyton tonsurans in 74% of patients and Microsporum canis in 26%. At week 8, the griseofulvin-treated group showed a cure rate of 76%, and the terbinafine- treated group 72%. At week 12, the efficacy of griseofulvin decreased to 44%, whereas the efficacy of terbinafine was 76%. Conclusion: Terbinafine constitutes an alternative for the treatment of tinea capitis. Recurrences were less frequent. No significant side effects were reported.