Atypical antipsychotics have been used to treat patients with schizophrenia for many years, but now there is increasing evidence of their utility in the treatment of mood disorders. In the past few years, several atypical agents have received regulatory approval for use in mania. The evidence shows that atypical antipsychotics are effective in the treatment of manic symptoms, either alone or in combination with traditional mood stabilizers, such as lithium and divalproex. Although emerging data indicate that atypical antipsychotics will be a promising addition to those therapies that are currently available for managing patients during the maintenance phase of bipolar illness, their potential in the long-term management of bipolar disorder remains to be fully explored. Aripiprazole is a recently released antipsychotic medication that differs from other atypical antipsychotic agents by its mode of action as a dopamine D2 partial agonist. It is administered orally and has a long half-life. Randomized studies have demonstrated the efficacy of aripiprazole compared with placebo in the treatment of acute relapse of schizophrenia and schizoaffective disorder, maintenance treatment of schizophrenia, treatment of acute mania, and prevention of manic relapse in patients who responded to the drug during a manic episode. Further studies are ongoing in bipolar and unipolar depression. Aripiprazole is generally well tolerated compared with other antipsychotic medications, although commonly reported side effects include extrapyramidal symptoms and motoric activation similar to akathisia. Further studies and postmarketing data will be helpful in providing additional information regarding the comparative safety, efficacy and tolerability of aripiprazole in the treatment of affective disorders.