Although there has been increased research and clinical attention given to the effects that physical activity has on quality of life among older adults, there is a lack of consistency surrounding the use of this term. As a result, attempts to examine what causes change in quality of life have been limited. This article critically reviews the literature on physical activity and quality of life in older adults. In so doing, attention is given to both quality of life as a psychological construct represented by life satisfaction as well as a clinical and geriatric outcome represented by the core dimensions of health status or health-related quality of life. The literature is also examined to identify potential mediators and moderators in the physical activity and quality-of-life relationship. Discussion of possible mediating variables reinforces the important role of perception when considering the beneficial effects that physical activity has on quality of life. From a public health perspective, understanding what may cause change in quality of life has significant implications for the design, implementation, and promotion of physical activity programs for older adults.