There is considerable scientific evidence documenting the health benefits associated with a physically active lifestyle. Despite this evidence, a high level of physical inactivity in many countries is placing a considerable burden on health care budgets. Country-specific estimates of the economic costs attributable to physical inactivity range from 1.2% to 2.5% of total annual health care expenditures. Despite the existence of effective physical activity interventions, their deployment in primary care has been limited. The results from a limited number of studies conducted in primary care settings demonstrate that the promotion of physical activity may be a cost-effective approach. Future studies of physical activity intervention are encouraged to contribute important cost-effectiveness analysis information to the emerging evidence in this area.