Neither experimental nor clinical data confirm the repeatedly published opinion that video-endoscopic surgery promotes tumor growth or the occurrence of implantation metastases in cancer patients. On the contrary, alterations due to pneumoperitoneum by the application of different gases, pressures, and temperatures might provide the basis for a new therapeutic approach to cancer surgery. Oncologically adequate resections defined by such terms as "no touch isolation" and "monobloc resection" can be performed video-endoscopically in a variety of intraabdominally or intrathoracically located cancers if a standardized technique is used. The benefit of video-endoscopic surgery is limited in large tumors, especially if they have reached the organ surface. There is still a major deficit in the clinical evaluation of video-endoscopic interventions in most oncologic diseases. Randomized studies comparing video-endoscopic and conventional surgery have been reported only for the resection of colorectal carcinoma. They show that laparoscopic resections can be performed with a minimum of postoperative complications to the same extent as conventional resections and offer several advantages during the early postoperative period. No reliable data from comparative trials are as yet available on the long-term results.