The general pathology in 120 necropsy-proven cases of multiple sclerosis has been compared with that of matched neurological and general controls. There was no significant difference in the incidence of coronary thrombosis, myocardial infarction, cerebral haemorrhage, thyroid atrophy and splenic haemosiderosis. There was also no significant difference in malignancy in the three groups. The implications of these findings with particular reference to immunopathology are discussed. 74% of patients with multiple sclerosis died from complications of the disease; 26% died from apparently unrelated diseases.