Family patterns for age at death were examined in a 40 year follow-up of 5209 men and women (2900 deceased, 2309 living) in the Framingham Study and their parents. Age at death of both mothers and fathers was significantly older for surviving offspring when compared to decreased offspring (p less than 0.0001). When longevity was assessed according to cause of death in the offspring, parental age at death was a significant predictor of death by coronary heart disease (CHD), but not for stroke or cancer. Multiple regression analysis for offspring with sudden CHD death revealed that mother's age at death was a significant predictor of age at sudden CHD death (p less than 0.0003) whereas father's age at death was a significant predictor of age at death in non-sudden CHD death (p less than 0.004). Life table analysis showed longest survival rates associated with both parents surviving to age 75 or older followed by mother only surviving to age 75 or older, then father only, and shortest survival with neither parent surviving to age 75. Longevity appears to be more strongly associated with maternal death age than parental death age. Proportional hazards analysis of risk factors associated with CHD revealed that systolic blood pressure, sex of the individual, and cigarette smoking were the most significant predictors of death age. These findings suggest that familial similarities for death age may be mediated primarily through shared CHD risk factors within families, either genetic or non-genetic.