The relationship between hypertension and performance on a test of free recall memory was explored in a geographically-defined population of free-living subjects 65 years and older. Those with diastolic but not isolated systolic hypertension had a significantly lower performance on the memory test, after controlling for general health status, antihypertensive medication use and other factors which might confound or modify this association. These findings from a population study confirm the results of prior investigations in smaller numbers of highly selected subjects and suggest that further study may lead to improved prevention of cognitive decline in the elderly.