Five former war prisoners of the Japanese were clinically evaluated and intensively investigated for evidence of neurological disease. On release from imprisonment 36 years previously they were known to have a single neurological problem each, attributable to nutritional damage to the nervous system (four had optic atrophy and one a peripheral neuropathy). The present assessment confirmed these persisting neurological problems; but in addition two patients were found to have extrapyramidal and one pyramidal disease, one was demented, and two had evidence of non-dominant hemisphere damage on psychometric testing. Nutritional damage to the nervous system may be permanent, and more extensive than usually recognized.