Social and health service utilization have been the subject of numerous studies, but most have examined service utilization from the perspective of the type of service delivered to older adults. To determine the factors that predict overall utilization of services, data that had been collected in 1975 for the General Accounting Offices' survey of "The Well-Being of Older Persons in Cleveland, Ohio" (1,609 non-institutionalized adults) were analyzed. Using path analysis, predisposing, enabling and need factors were examined to determine their relationship to the use of formal and informal health and social services. Results showed that predisposing variables (age, sex, race, education, and marital status) had a small direct effect on utilization and an indirect effect through their influence on subsequent stage variables. For the enabling variables (perceived income, income, and social support) only social support had an indirect and direct effect. Need factors were all directly related to service utilization. Perceived need was more important than all other predisposing, enabling and need factors. The findings emphasize the importance of perceived need and question the importance of predisposing and enabling factors in predicting service utilization. (Author/JAC)