Several large, randomized controlled trials have demonstrated the efficacy of topiramate in migraine prophylaxis in adults. However, there are limited data about the use of topiramate in migraine prophylaxis in children. We conducted this single-center, double-blind, placebo-controlled trial to evaluate the efficacy and safety of topiramate in the prophylaxis of migraine in children. A total of 44 children with migraine were randomized using random number tables to receive topiramate (n = 22) or placebo (n = 22). The total duration of treatment was 4 months, including a baseline period of 1 month during which topiramate was titrated weekly in 25-mg increments to 100 mg/d in 2 divided doses or to the maximum tolerated dose. The titration was followed by a 12-week maintenance phase during which topiramate was given in 2 divided doses. The primary outcome measures were the reduction in the mean migraine frequency and severity of headache. Secondary outcome measures included the number of times analgesics were required for a month for acute attacks and functional disability. Functional disability was measured by comparing school absenteeism and Pediatric Migraine Disability Assessment Scale (PedMIDAS). The decrease in mean (+/-SD) monthly migraine frequency from 16.14 (+/-9.35) at baseline to 4.27 (+/-1.95) at the end of the study in the topiramate group was significantly greater as compared with a decrease from 13.38 (+/-7.78) to 7.48 (+/-5.94) at the end of the study in the placebo group (P = .025). The difference in number of rescue medications used for topiramate and placebo was not statistically significant (P = .059). There was a statistically significant decrease in the PedMIDAS score from 50.66 (+/-32.1) to 10.42 (+/-6.39) at the end of the study in the topiramate group compared with a decrease from 42.66 (+/-27.5) to 23.7 (+/-19.1) at the end of 4 months in the placebo group (P = .003). The decrease in school absenteeism was significant with topiramate compared with placebo (P = .002). Weight loss, decreased concentration in school, sedation, and parasthesias were important side effects with topiramate. Most of these side effects were mild to moderate and were not significant enough to cause dropout from the study.