Mania in old age is not as rare as it was once thought to be. It may constitute up to 5 per cent of admissions in the psychogeriatric department. The clinical picture, for the most part, seems to correspond with mania in younger patients, although some patients may have atypical presentations. Secondary mania should be excluded first, before a firm diagnosis of primary affective disorder is made. The prognosis and treatment of late onset mania do not seem to differ appreciably from those in younger patients.