Twelve patients with Cushing's syndrome (11 females, 1 male) who were examined for psychopathologic alterations in the course of the endocrine disease during the years 1960-61, were reexamined in 1976 regarding psychiatric sequelae after treatment. Ten patients had been treated by adrenalectomy, one patient by radiotherapy of the hypophysis, and one patient had refused any treatment. The average lapse of time from operation to reexamination or death (five patients) was 15 2/3 years. In seven patients it had been possible to stop completely the excessive production of adrenal hormones. Corresponding the long-term result was favorable, with complete recovery of the ability to work. The previous symptoms of the endocrine psychosyndrome disappeared almost completely. There was no permanent alteration of personality and the vital dependence on hormonal substitution was well tolerated. In four of the five patients with an unfavorable course of the disease it had not been possible to stop the excessive production of adrenal hormones. These patients became increasingly invalid and had to be cared for. Symptoms of chronic organic brain syndrome developed. In contrast to the course of panhypopituitarism where nonspecific personality factors are of considerable importance, in Cushing's syndrome the long-term prognosis depends entirely on the successful stoppage of the overproduction of adrenal hormones. The artificial subsitution is not necessarily a disadvantage for the psychic functioning of the patient.