The purpose of the present study was to evaluate changes in metabolic parameters after switching to aripiprazole in Japanese population. In this 1-year observation study, following a switch to aripiprazole, 32 patients with schizophrenia were observed and assessment was done of bodyweight, total cholesterol, triglyceride, serum prolactin level, and corrected QT (QTc) interval. Significant reductions were observed in these parameters other than QTc interval. Given known detrimental metabolic and hormonal effects of some atypical antipsychotics, a switch to aripiprazole may warrant serious consideration also in Asian patients who suffer those side-effects.