A study was carried out of 30 consecutive patients with withdrawal psychosis who in the period 1972 to 1975 were admitted to a psychiatric department or were attended by the department while hospitalized in a somatic department. There was a clear majority of women among cases of psychosis following drug withdrawal (15 as against four) and a clear majority of men among cases of psychosis following alcohol withdrawal (nine as against two). Competing pathogenetic factors could be considered present in most cases in the last mentioned group. In most cases the abrupt cessation took place in conjunction with admission to hospital, most frequently surgical cases or cases of acute drug toxication. In other cases abrupt cessation was decided upon by the patient himself. Frequently predelirium treatment was either omitted or was given in the form of neuroleptics. Approximately a quarter of the patients initially denied their abuse. The study indicates that withdrawal psychosis can make its debut or become manifest at so late a stage as about the 14th day of the withdrawal phase following use of benzodiazepines and d-propoxiphene. It is further indicated that abrupt cessation of benzodiazepines taken in "therapeutic" doses for several years in some instances can give rise to a withdrawal psychosis.