Follow-up observations were made of 92 white patients with early-onset Alzheimer's disease to determine the demographic, clinical, and neuropsychological factors predictive of institutionalization or death. The cumulative mortality rate 5 years after entry into the study was 23.9%, compared with an expected rate of 9.5%. The 5-year cumulative rate of admission to nursing homes was 62.8%. The language ability of the patients on entry to the study, their scores on a brief screening test of cognitive function, and their overall ratings of clinical dementia were found to be predictors of subsequent institutional care and death. The age of the patients had a significant modifying effect on these predictive factors, resulting in a greater risk of institutionalization and death in younger patients with severe cognitive impairment as compared with older individuals with the same degree of dysfunction.