From June 1987 to June 1990, an anterior mediastinotomy with opening of the pericardium was performed in 11 patients (mean age 67.8 years) to evaluate resectability of left-sided centrally located bronchogenic carcinoma. In 3 patients (27.3%), extensive intrapericardial involvement was found which precluded complete resection. Intrapericardial extension without complete invasion of the pulmonary vessels was present in 2 patients (18.2%) who subsequently underwent an intrapericardial pneumonectomy. In 6 patients (54.5%), no intrapericardial tumour was present. There was no perioperative mortality. One patient required redrainage of the pleural cavity because of a postoperative pneumothorax. In total, 4 patients (36.4%) underwent intrapericardial pneumonectomy, 6 (54.5%) were treated by radiotherapy and 1 (9.1%) by chemotherapy. In left-sided, centrally located tumours, opening the pericardium during anterior mediastinotomy yields additional information about the degree of tumour invasion and the feasibility of performing an intrapericardial pneumonectomy. In this way, an exploratory thoracotomy is avoided and the risk of irresectability is greatly reduced.