Mood stabilizers and atypical antipsychotics are commonly combined for the treatment of bipolar mania. The aim of this study was to compare the effectiveness and tolerability of topiramate and divalproex in combination with risperidone for treating acute mania patients in a naturalistic treatment setting. Seventy-four patients who met the DSM-IV criteria for bipolar mania were enrolled in this study. In order to assess the efficacy and the extrapyramidal symptoms (EPS), the Young Mania Rating Scale (YMRS), Clinical Global Impression (CGI) and Simpson-Angus Rating Scale (SARS) were measured at the baseline and at weeks 1, 3 and 6. From the baseline to the endpoint, the YMRS and CGI scores were reduced by 67.9% and 56.6% in the topiramate plus risperidone group (TPMG). The YMRS and CGI scores were also reduced by 63.7% and 58.2% in the divalproex plus risperidone group (DVPG). The weight and body mass index (BMI) increased significantly by 3.6% and 3.3% from the baseline to the endpoint in the DVPG, while they decreased by 0.5% and 0.4%, respectively, with no significant difference in the TPMG. There were no serious adverse events in either group. Despite the methodological limitations, topiramate was effective and tolerable for treating acute mania and may also be a promising alternative to a weight-gain liable mood stabilizer (MS) such as divalproex.