The study found distinctly different interrelationships among factors affecting social service use by Mexican American, Puerto Rican, and Cuban elderly. Twenty-nine variables and data selected from a 1979-80 15-state survey of 1,805 noninstitutionalized Hispanic individuals aged 55 and over were categorized by the Andersen-Newman model of service use and analyzed to construct theoretical models for social service planning. Researchers found that differing cultural background, social history, and social situation affected use of social services by Hispanic elderly. Number and kind of predictors of social service use differed among the groups. Predictors of service use by Puerto Rican elderly in order of importance were need for service, knowledge about services, fequency of visiting with friends, income, difficulty with language, number of children and daily living abilities. Predictors for Cuban elderly were need for service, knowledge about services, income, daily living abilities, age, citizenship status, age density, and self-rated health status. Predictors for Mexican American elderly were need for service, knowledge about services, income, and 14 other factors including involvement in social networks of friends and church activities and higher levels of education and language ability. Appended tables and figures illustrate predictive models for each group. (LFL)