Aim. We report on nine highly selected patients in whom the resection of the tumor was only possible with cardiopulmonary bypass (CPB). Methods. Between November 1996 and November 2009, nine patients with non-cardiac tumors underwent surgery under CPB. Indications were: infiltration of the pulmonary vein in the left atrium (four cases), one case where the tumor (a paraganglioma apparently located in the subcarinal space) was actually in the atrium wall, one mediastinal liposarcoma with massive infiltration of the pericardium and the main pulmonary artery, and three tracheal tumors (2 cylindromas and 1 carcinoid). Results. Indication for CPB was decided preoperatively in 7 cases and intraoperatively in the other 2 patients. Cardiac infiltration was confirmed with intraoperative transesophageal cardiac echography in 2 patients, which proved to be very useful. Concerning postoperative complications, one patient died intraoperatively because it was impossible to stop the CPB after reconstruction of the bifurcation of the main pulmonary artery. Although the duration of the operation was significantly increased by the use of cardiopulmonary by-pass, it did not influence postoperative recovery in any of the other eight patients, as far as bleeding or infection was concerned. In one patient, a thoracic drain had to be replaced due to a partial pneumothorax. In another patient a partial dehiscence of the neo-carina was conservatively treated. Long-term results were influenced by the initial pathology of the patient. Conclusion. CPB provides the possibility of safely re-secting intrathoracic tumors invading cardiac structures that were previously inoperable. This can be achieved with an acceptable level of risk and - in very selected cases - may achieve long-term survival.