Since November 1985, we performed Intra Operative Radiation Therapy in 53 cases, essentially in gastric cancer (20 patients) and in pancreatic cancer (22 patients). Mortality and morbidity were not increased by the use of Intra Operative Radiation Therapy. Our follow up is too short to get any valid conclusions about IORT in gastric cancer. However, for unresectable pancreatic cancer, we observed an improvement of the survey when patients were treated by "Surgery, IORT and External post operative radiotherapy". We also studied the relief of abdominal and back pain of unresectable pancreatic cancer: in our experience, the survey was longer and more confortable for patients treated with surgery and IORT. In conclusion it appears that today IORT is surely a good palliative treatment for unresectable pancreatic cancer, and longer experience is needed to conclude for resectable pancreatic cancer and for gastric cancer.