Four hundred young-, middle-, and old-old adults responded to a banery of quizzes dealing with life satisfaction and objective aging knowledge in the physical, psychological, and social domains. Analyses incorporated domains of aging knowledge, life satisfaction, age, gender, and demographic variables. Both means difference and regression analyses were computed. Significant age group, gender, and life satisfaction differences were found for the three aging knowledge domains. For successive age groups, knowledge of aging decreased, with females knowing less than males. The greater knowledge of aging, the higher the life satisfaction. The demographic variables education, financial status, health, living arrangement, and volunteerism were significant covariates for knowledge of aging. Results from this study indicate that knowledge of aging in specific domains varies among older adult age groups and is associated with life satisfaction.