A significant number of patients with severe angina or intractable atypical chest pain referred for coronary arteriography are found to have normal coronary vessels. To determine what therapeutic or economic benefit may be derived from these studies, we analyzed the data of 72 consecutive patients with normal vessels referred for cardiac catheterization because of severe chest pain. The clinical status and hospitalizations were analyzed for the 2 year period before and the 2 year period after angiography. There were no deaths or myocardial infarctions. Although 47 were thought to have angina and 25 atypical pain before catheterization, the chest pain was reclassified with only 15 continuing to have anginal pain, 40 atypical pain, and 17 no pain. Functional improvement by at least one New York Heart Association class occurred in 74 percent of patients with 36 (50 percent) having no functional limitation. The use of cardiac medications was also significantly reduced. Despite functional improvement, no change in employment states could be demonstrated. The use of medical facilities was significantly less, the average number of hospital days per patient declining from 17 to 3.9 and hospitalization decreasing from 1.5 to 0.4. The result was a significant decrease in estimated hospital costs. We conclude that in patients referred for coronary angiography for severe chest pain, documentation of a normal coronary arteriogram significantly alters the clinical assessment of symptoms, improves functional status, modifies medical therapy, and reduces hospitalization and medical costs. These therapeutic and economic benefits deserve consideration in the evaluation of coronary angiography for its overall effectiveness.