We conducted a self-administered questionnaire survey to a total of 5239 elderly persons in four areas in Japan in 1993, which inquired about past lifestyles and present social activities. Based on the survey data, we first developed social activity measures, and then examined associations of the present total social activity measure with past lifestyles and physical conditions. The lifestyles significantly associated with high social activity after 65 years of age were 'high educational attainment'; having been 'healthy', 'plump', 'physically active' and 'having had hobbies' at about 50 years of age; and having 'frequent intake of many kinds of foods' during 30-50 years of age. Intake during 30-50 years of age of Japanese-style foods (rice, soybean paste soup, bean curd, pickles), noodles, beans, plant roots and potatoes was not significantly linked with the social activity levels at old age in either males or females. The same was true for smoking and drinking habits at about 50 years of age. Our findings essentially suggest the importance of a positive attitude at middle age to maintain and promote health status and improve lifestyles in order to attain high social activity at old age.