The clinical effect of the GABAergic drug gabapentin was evaluated in 11 patients with spinocerebellar ataxia type 6 (SCA6). The total period of gabapentin treatment was 4 weeks, and outcome measures were determined with the International Cooperative Ataxia Rating Scales (ICARS) and postural sway studies. At week 4, 5 patients showed a decrease of the ICARS values by more than 10% compared with the pre-treatment baseline. Eight patients showed a more than 10% decrease of the sway area (SA) and/or sway path length (SPL) values in postural sway studies. The ICARS values and SA/SPL values were not necessarily consistent in each patient, but 3 patients showed a more than 10% decrease in the ICRAS, SA, and SPL values at week 4 when compared to the pre-treatment baseline. As a whole, the efficacy of gabapentin was not statistically confirmed in the 4-week trial because of the variation in efficacy in each patient, but the data are indicative that some SCA6 patients could benefit from gabapentin treatment.