Atypical antipsychotics are characterised by a low propensity for causing acute and tardive extrapyramidal symptoms and an increased efficacy against positive and negative symptoms in schizophrenia. A growing literature suggests clozapine and other atypical antipsychotics, including olanzapine, risperidone, and possibly quetiapine and ziprasidone, are also effective in the treatment of bipolar disorder, particularly the manic phase. Symptoms that are refractory to other drugs may respond to these agents. However, antipsychotic treatment can be associated with serious adverse effects, and caution needs to be exercised in the prescription of these agents.