While mania usually occurs as a phase of manic-depressive disease, it can occur in association with organic dysfunction--medical and pharmacological--in patients with no history of affective disorder. In reviewing the literature, we have found that mania occurs secondary to drugs, infection, neoplasm, epilepsy, and metabolic disturbances. These cases are best considered secondary manias. They suggest that mania--like, for example, hypertension--is a syndrome with multiple causes and that with further research many manic syndromes currently considered primary will be shifted into the secondary category. Furthermore, the concept of secondary mania casts doubt on any unitary or single-agent hypothesis of the etiology of mania and supports the notion of a continuum of psychopathologic syndromes. Clinicians are alerted to the existence of this syndrome and are urged to screen for it when conditions warrant.