BACKGROUND With emphasis today on cost containment in health care, the results and costs of cardiac operations in elderly patients are being scrutinized. METHODS Our computerized database was used to obtain the characteristics of patients undergoing cardiac operations from January 1990 to July 1994. A study group of 628 patients aged 70 years and over was identified, and comparisons were made between them and adult patients less than 70 years of age. RESULTS In the elderly group the 30-day mortality was 33 of 628 (5.3%), and the overall hospital mortality was 40 (6.4%). During this time the 30-day mortality for all adult patients less than 70 years old was 49 of 1787 (2.7%; p < 0.003) and the hospital mortality was 59 (3.3%; p < 0.001). The mean length of postoperative hospital stay (days +/- standard error) in all surviving patients aged 70 years and over was 11.6 +/- 0.4 days, compared with 8.5 +/- 0.2 days in patients less than 70 years old (p < 0.001). Over the time of the study the length of stay in patients less than 70 years old declined from 9.6 +/- 0.4 to 7.2 +/- 0.6 days, whereas it stayed the same for elderly patients. The 30-day mortality and length of stay increased with the risk category of the Parsonnet model. The mean hospital charge for patients aged 70 and over was 114% of that for younger patients. CONCLUSIONS Although mortality, length of stay, and hospital charge are increased in patients 70 years of age and over, they are not excessively so. The results support the continued performance of cardiac surgical procedures in select elderly patients.