Patients with both resectable lung cancer and coronary artery disease require preoperative cardiac evaluation in order to determine and prevent the surgical risk and to discuss the desirability of preventive myocardial revascularization. The results of thoracic surgery in coronary disease patients have been studied in a series of 51 patients operated upon for lung cancer at the Marie Lannelongue hospital, Paris, between 1985 and 1988. Thirty-two patients underwent non invasive exploration prior to surgery (exertion ECG in 22, myocardial radioisotope scanning in 10); 35 patients had coronary arteriography at the last moment, and 9 asymptomatic patients with an old history of myocardial infarction had no specific exploration. Forty-nine patients had lung surgery alone, preceded in 5 cases by percutaneous coronary angioplasty; one patient had pulmonary surgery and coronary surgery simultaneously, and another patient had coronary surgery first, later followed by lung surgery. No perioperative death was due to cardiovascular causes. A 75-year old male patient died of respiratory failure 30 days after lobectomy. The postoperative period was totally uneventful in 39 patients. No perioperative myocardial infarction was recorded; 4 patients experienced an episode of thoracic pain with ECG signs of myocardial infarction but no rise in serum enzyme concentrations. One patient had a cerebral vascular accident responsible for hemiplegia. Two late sudden deaths, probably of cardiac origin, occurred 4 and 11 months respectively after surgery. The actuarial survival rate at 3 months was 48 percent. In all survivors, the coronary symptoms were controlled by medical treatment. It seems, therefore, that perioperative complications in this type of patient can be avoided by preoperative evaluation of the coronary disease and by preventive myocardial revascularization in case of critical coronary stenosis.