The case for reduction of air pollution has been predicated primarily on the frequently observed relationship between pollution and mortality and morbidity. Because pollution control usually involves costs, a rational public policy will weigh the benefits against the costs. This study investigates another potential benefit from pollution reduction: namely, decreased use of medical care. We find a strong relationship between particulate matter and inpatient and outpatient care at ages 65-84 across 183 metropolitan statistical areas (MSAs). The relationship is statistically significant at a very high level of confidence even after the region and population size of the areas, education, real income, racial composition, use of cigarettes, and obesity are controlled for.