The management of bipolar disorder presents challenges for the clinician who is often required to prescribe a variety of medication regimes for the different phases of the illness. With a range of pharmacological actions, quetiapine fumarate is a useful option in such circumstances. Initial studies have yielded encouraging results: quetiapine fumarate is effective as monotherapy or as an adjunct to mood stabilizers in mania and in the maintenance phase, and as monotherapy in bipolar depression. The extended-release preparation with once-daily dosing may potentially enhance adherence. Studies of this formulation reveal an efficacy profile matching the immediate-release preparation. However, precise dosing schedules, metabolic consequences and the risk of other side effects will need to be considered in establishing quetiapine fumarate in the management of any individual patient.