The purpose of this study was to evaluate the efficacy of topiramate in the treatment of acute manic symptoms. Fourteen patients, admitted with an acute manic episode, were treated with topiramate. All required supplementation therapy with benzodiazepines. Nine patients received topiramate as monotherapy; four of them required zuclopenthixol acutard 100 mg/48 h intramuscularly (im) for not more than 6 days. In three treatment-resistant patients, topiramate was added to the existing therapy. Finally, in two patients topiramate was coadministered with an antipsychotic from the beginning. Patients were assessed every week for 4 weeks with the Bech and Rafaelsen Mania Scale (BRMS). Mean BRMS scores declined from 26.2 to 11.6 in the fourth week (P<.001); a significant decline (P<.001) was observed after the first week. Response rate (> or = 50% reduction of BRMS) was 61.5% (8 out of 13 patients). All patients tolerated topiramate well. Reduced appetite and weight loss was observed in four patients; however, two patients presented weight gain. These preliminary findings provide support for a modest efficacy of topiramate, especially as monotherapy, in the treatment of acute mania.