Women, ethnic minorities and uninsured persons receive fewer cardiac procedures than affluent white male patients do, but rates of use are crude indicators of quality. The important question is, do women, minorities, and the uninsured fail to receive cardiac procedures when they need them? To measure receipt of necessary coronary artery bypass graft (CABG) surgery and percutaneous transluminal coronary angioplasty (PTCA) overall by patient sex, ethnicity, and payer status; and by availablity of on-site revascularization, a retrospective, randomized medical record review was conducted in 13 of the 24 hospitals in New York City that provide cornonary angiography. Although revascularization procedures are substantially underused, no variations in rate of use by sex, ethnic group, or payer status were seen among patients treated in hospitals that provide CABG surgery and PTCA. However, underuse was significantly greater in hospitals that do not provide these procedures, particularly among uninsured persons.