Objective: The evaluation of the influence of open-heart surgery on the survival of patients with co-existent surgically amenable lung cancer stages I and II., Methods: A retrospective, observational study was conducted in a tertiary centre for cardiothoracic surgery. From 1988 to 1995, 121 consecutive patients underwent pulmonary resection for stages I-II primary non-small cell bronchogenic carcinoma. Eighty seven of them had merely a lung carcinoma necessitating resection, 34 had in addition defined coronary-artery disease and consequently were also subjected to open-heart surgery. Results were statistically computed., Results: Follow-up was complete in 117/121 patients, 96.7% (83/87, 95.4% and 34/34, 100% in respective groups). Both groups were matched with regard to preoperative features possibly influencing survival. Median long term survival time was 4.3 years overall, 5.8 years for patients merely undergoing lung resection and 4.2 years for them undergoing open-heart surgery as well; this difference was not statistically significant (log-rank test: chi2 0.92, df= 1, P = 0.34), indicating no or limited influence of open-heart surgery on survival of patients with surgically amenable co-existent lung carcinoma. No relationship was found between survival and age, tumour stage, and histopathology. However, metastatic disease as cause of death was significantly increased in patients undergoing open-heart surgery (5/8 vs. 10/33, P = 0.0898), indicating a possible promotion of metastatic spread of co-existent lung carcinoma by this procedure. Overall perioperative mortality rate was 10/121, 8.3%, for the greater part the result of a relatively high mortality rate in the group of patients undergoing heart as well as lung surgery (6/34, 17.6%), underscoring the great risks involved in these patients, the mortality rate for lung resection alone being comparably low 4/87, 4.6% (P = 0.0191)., Conclusion: Open-heart surgery for defined coronary-artery disease in patients with surgically amenable lung carcinoma carries a substantially higher perioperative risk, but has no influence on long term results. Metastatic spread is possibly promoted by open-heart surgery. Optimal treatment, consisting of complete revascularization and appropriate lung resection, is therefore sufficiently justified by these results.