The symptomatic course of bipolar disorder (BPD) is chronic and dominated by depression. As recurrence rates are high, maintenance therapy is required. Although efficacious, mood stabilizers may be hampered by poor adherence, and second-generation antipsychotic medications may be associated with weight gain and metabolic abnormalities. There is evidence to suggest that aripiprazole is beneficial in major depressive disorder and BPD with depression. We therefore investigated 2-year clinical outcomes with aripiprazole adjunct therapy at 5 to 15 mg once daily alongside a mood stabilizer in 40 patients with BPD. All patients experienced marked improvements in Montgomery-Åsberg Depression Rating Scale scores by 6 weeks and substantial reductions in Clinical Global Impressions Scale scores by 6 months. All patients were able to return to optimal or premorbid functioning by 6 months to 1 year. By 1 year, all patients made a complete functional recovery on the Sheehan Disability Scale. Improvements were maintained on all measures up to 2 years. There were minimal adverse events, all of which decreased during therapy. Our findings indicate that aripiprazole adjunct treatment is safe and effective as an acute and maintenance therapy for BPD. However, the findings will need to be replicated by larger studies.