Women increasingly outnumber men in the US population (Arber & Ginn, 1993), but most research has been conducted with men (Stacey & Olesen, 1988). The purpose of this study was to determine whether older men and women differ in their participation rates and in their responsiveness to a health intervention. Three hundred sixty-three health maintenance organization members with osteoarthritis, 60 years of age or older, were randomly assigned to a control group or to receive social support, education, or a combination of education and social support, education, or a combination of education and social support. Of the 363 randomly assigned members, 245 completed all of the follow-up assessments. Men and women volunteered in proportion to their representation in the osteoarthritis population. Although the genders differed in several ways, the interventions were equally effective for men and women, and the study results applied to both genders.