We evaluated antiischemic therapy in elderly nursing home residents with a diagnosis of coronary heart disease (CHD) using a population-based data base with over 300,000 residents (1992-1995) of all Medicare/Medicaid-certified nursing homes of five states. We identified 72,263 patients age 65 years or older with a diagnosis of CHD. We examined data collected with the federally mandated Minimum Data Set, drug information, and Medicare hospital claims. Antiischemics were defined as beta-adrenergic blockers, long-term nitrates, and calcium channel blockers. We determined factors associated with use of the drugs by logistic regression. Antiischemic therapy was inversely related to age and cognitive and physical functioning, but positively associated with recent hospitalization and concomitant cardiovascular diseases. beta-Adrenergic blockers were least likely to be administered regardless of age, gender, or cognitive or physical function. We conclude that antiischemic therapy in nursing home residents may not be optimal.