Objectives: In an effort to reduce allogeneic blood transfusions in patients undergoing elective surgery for lung cancer, we investigated the effectiveness of a method of processing shed blood with an automated device for intra operative blood salvage (IOBS) and filtration with a 3rd-generation polyester filter to remove tumor cells. Methods: Sixteen patients were operated on for different types of lung cancer. We searched for malignant cells in pre- and postprocessed shed blood employing density gradient centrifugation, staining of cytospins with hematoxylin-eosin, and antibodies to human cytokeratins. Results: In 9 out of 16 cases (56%), neoplastic cells were detected in prefiltration samples, but none were found in postfiltration cytospins. Conclusion: IOBS combined with appropriate filtration could be a very useful and safe tool in reducing allogeneic blood transfusion in cancer patients.