The value of exercise to the health and well-being of older adults has received considerable attention in recent years. Factors that influence older adults to move from an inactive to an active stage of exercise have received much less attention, but it is generally concluded that exercise self-efficacy (i.e., judgments of one's competence) holds more promise than any other factor. Accordingly, this article develops a conceptual model of exercise self-efficacy and its predictors among older adults. The special circumstance of low socioeconomic status older adults is given particular attention, because of their poor health and low activity levels. Data from two focus group sessions are drawn upon to supplement what is otherwise a conceptual discussion of age, socioeconomic status, sense of control, and self-efficacy.