Since November 1985, we have performed 54 Intra-Operative Radiation Therapy (IORT) interventions, essentially in gastric cancer (20 patients) and in pancreatic cancer (22 patients). Mortality, morbidity, and average of survival rates were compared with a non-randomized control group: mortality and morbidity rates were similar in the two groups, with or without IORT. The follow-up period was too short for any valid conclusions about IORT in gastric cancer to be reached. However, in the case of unresectable pancreatic cancer, a significant difference was observed in survival rates when patients were treated by surgery alone or surgery and IORT (4.7 months), and when they were treated by surgery, IORT and external postoperative radiotherapy (8.9 months) (p less than 0.05). The study also examined the relief of abdominal and back pain in patients with unresectable pancreatic cancer: in our experience, survival was longer and more comfortable for patients treated with surgery and IORT. In conclusion, it appears that today IORT is without doubt a good palliative treatment for unresectable pancreatic cancer, but more experience is needed before a conclusion can be reached regarding resectable pancreatic cancer and gastric cancer.