Despite the well-known health benefits of physical activity (PA), most midlife and older adults lead sedentary lifestyles. Anglo American women and Mexican Americans of both genders are two of the least physically active groups. We conducted three focus groups to identify attitudes and beliefs about PA among Mexican American and Anglo American midlife women. Our long-term goal was to identify culture-specific interventions that promote long-term PA continuation. Significant differences were found between the two groups. While Anglo American women valued individual outcomes, and spoke of personal factors promoting or preventing exercise, Mexican American women viewed PA as prescriptive, important for restoring health, and cited family responsibilities and family attitudes as factors that promoted or prevented them from exercising. We found that in order for PA interventions to be successful in each group, they must be tailored to the values of each cultural group.