Sixty-five patients primarily referred for erectile impotence were investigated. Information was obtained from patients and their partners. The demographic data are compared with those from a non-impotent psychiatric out-patient group, matched for age. Results indicate that impotent cases do not form a homogeneous population and can be classified into three fairly distinct groups. These groups differ in age, marital status, sex drive, pre-marital and post-marital relationships, duration of illness, etc. Group 1 develop impotence because of anxiety in sexual situations. Group 2 react to the sexual response and personality of their partners, while Group 3 decline, perhaps from inherent constitutional causes. Factors such as religious restrictions, sexual taboos, alcoholism and homosexuality do not appear to be of any aetiological importance.