In order to pursue the question of excess mortality due to chronic brain syndrome (CBS), 330 residents of a home for the aged were independently evaluated prior to admission by psychiatrists and by general physicians. Five years later, their medical records were searched to determine: 1) age on admission, 2) diagnosis of CBS on admission, 3) physical status on admission, and 4) if death had occurred, the age at death and the cause of death. Women outnumbered men by 3:1. Subjects with CBS outnumbered those without CBS by 2:1. A previous mortality study on 145 aged subjects at the same institution provided an excellent frame of reference for this investigation. Among the men there was no difference between the mortality rates for those with CBS and those without. Among the women a statistically significant difference in mortality was found between those with CBS and those without. Women with CBS and a "poor" physical status had the highest mortality rate. Those who initially had CBS died significantly sooner even if their admission physical status had been "good." Their mortality rate exceeded that for women with a "poor" physical status who did not have CBS. Bronchopneumonia caused death twice as often in subjects with CBS as in those without CBS, both among men and women. It is concluded that CBS per se is a significant factor in increasing mortality in the aged.