With the increasing age of patients and the progression of degenerative pathologies, the management of aortic stenosis (AS) with coronary artery disease is becoming more frequent. Reported results of combined valve and coronary surgery are equivocal especially with respect to the increased risk compared with aortic valve replacement without coronary surgery. The authors assessed the results of combined surgery by comparing two groups of patients with AS operated between 1979 and 1991: 122 patients with coronary lesions undergoing combined valve and coronary surgery (Group I) and 122 patients without coronary artery disease undergoing isolated aortic valve replacement (Group II) and paired with Group I patients for 5 prognostic factors (age, sex, functional status, date of surgery and left ventricular ejection fraction). Pairing the patients provided comparable populations for these 5 factors. The average age was high (68 years in Group I with over 50% of patients over 70 years of age) and most patients were in functional classes III or IV (67% in Group I). In Group I, 67% of patients had multivessel disease (average 2 vessel disease). Aortic valve replacement was associated with an average of 1.7 coronary bypass grafts per patient. Myocardial protection was the same in all cases using cold potassium enriched cardioplegic solutions. Operative mortality was 10.6% in Group I compared with 4.9% in Group II (NS) and the respective perioperative infarction rates were 6.6% and 0.8% (p < 0.02). Seven year actuarial survival rates were 71.8% in Group I and 74.9% in Group II (NS) without any increased late mortality in Group II.(ABSTRACT TRUNCATED AT 250 WORDS)