Seventh-day Adventists (SDAs) are members of a conservative Protestant denomination who neither drink nor smoke; 41% are vegetarians. Their age distribution shows a significant proportion of older persons. In 1958, a longitudinal study of 47,800 California SDAs was mounted to investigate the association of life habits with mortality and life expectancy. The study demonstrated that SDAs had a longer life expectancy than the general population and for most cancer sites had significantly lower mortality rates. Since 1974, over 70,000 SDAs were enrolled in a prospective study seeking to determine morbidity from cancer and other leading diseases and to ascertain which factors in their unique lifestyle are associated with their apparent longevity and reduced disease risk. The two separate studies have some 12,000 common enrollees with comparable assessments of lifestyle characteristics. Objectives of this research are fivefold: 1) to ascertain the living/dead status of 6,000 persons whose follow-up stopped in 1965, thus providing a 22-year mortality follow-up; 2) to analyze long-term longitudinal results in terms of the epidemiological correlates of longevity; 3) to compare mortality statistics of the SDA population with a separate population from the general public which had been independently and concurrently studied; 4) to determine what changes occur in nutritional and lifestyle factors in a 16-year period among the elderly and how such changes impact subsequent morbidity and mortality; 5) to determine the factors that characterize persons who successfully survive the Bereavement period following death of a spouse. This large prospective study based on available data resources provides a unique and cost-effective opportunity to examine the effects of lifestyle characteristics on longevity and the multicausal process of aging. Furthermore, it provides the potential for disentangling a large number of confounding variables which in the past have hampered related research efforts. Investigation into the longevity of the oldest members of a long-lived group seems to be appropriate at a time of steady increase in the number of elderly persons in the general population.