This study aimed to determine the rate of unipolar mania and compare its characteristics with those of other bipolar affective disorders in a psychiatric hospital in the Fiji Islands. Fifty-one patients with unipolar mania seen between January 1999 and October 2000, had their diagnosis confirmed using the Schedules for Clinical Assessment in Neuropsychiatry and the International Classification of Diseases, 10th edition. Their demographic and clinical characteristics were compared with those of 31 manic-depressive patients seen during the period under review. Unipolar mania constituted 47.2% of the bipolar affective disorders in this sample. The frequency of episodes, duration of affective illness, mean age at onset, gender distribution, marital status, employment status and race were not significantly different for the unipolar manic and manic-depressive groups (p > 0.05). Family history of major psychiatric morbidity was 9.8% for the unipolar manic patients and 22.6% for the manic-depressive group (p > 0.05). Recurrent unipolar mania may be considered a useful category based on its high rate, although its demographic and clinical characteristics do not clearly distinguish it from manic-depression.