INTRODUCTION:The aim was to examine associations between midlife cardiovascular health (CVH) and 20-year cognitive decline among blacks and whites. METHODS:Midlife CVH metrics (American Heart Association's Life's Simple 7) were calculated and examined in relation to midlife and 20-year change in cognitive function among 13,270 whites and blacks from the Atherosclerosis Risk in Communities Cohort Study. We used linear mixed models to estimate adjusted associations of midlife CVH with midlife cognitive status and change. RESULTS:Higher midlife (Life's Simple 7) scores and individual metrics, particularly blood pressure and glucose, were associated with better midlife cognition and reduced 20-year decline. Midlife CVH 20-year neuroprotection was more pronounced among whites than blacks. DISCUSSION:Better midlife CVH was associated with higher midlife and reduced decline in cognitive function 20 years later. However, the benefits of midlife CVH on cognition were stronger for whites than for blacks. Our findings suggest that improved midlife CVH may promote enduring cognitive health.