We evaluated the effectiveness of aripiprazole among bipolar patients who had switched to this medication as a result of difficulty maintaining on their prestudy atypical antipsychotics (AAPs) because of subsyndromal mood symptoms or intolerance. This study included 77 bipolar patients who were in syndromal remission with an AAP as monotherapy or with an AAP combined with a mood stabilizer(s) who needed to switch from their present AAP because of subsyndromal symptoms or intolerance. At 24 weeks after switching to aripiprazole, the remission rates on the Montgomery–Åsberg Depression Rating Scale (MADRS) and on both the MADRS and the Young Mania Rating Scale were increased significantly in the full sample and in the inefficacy subgroup. In the inefficacy subgroup, the MADRS score change was significant during the 24 weeks of study. Total cholesterol and prolactin decreased significantly after switching to aripiprazole. The proportion of patients who had abnormal values for central obesity and hypercholesterolemia decreased significantly from baseline to week 24. These findings suggest that a change from the current AAP to aripiprazole was associated with improvement in subsyndromal mood symptoms and several lipid/metabolic or safety profile parameters in patients with bipolar disorder with tolerability concerns or subsyndromal mood symptoms.