Intra Operative Radiation Therapy (IORT) has been routinely used for the past 20 years. It is a feasible treatment, with a reasonable cost and an acceptable acute and late toxicity. There is so far no strong randomized trial demonstrating that IORT can improve overall survival. Nevertheless, in many institutions it is recognized as an efficient treatment in selected patients. In case of locally recurrent disease an incomplete gross resection is often the only choice; IORT in such a situation has led to very encouraging results. For locally advanced deep seated primary tumors IORT seems to improve local control. In the near future IORT should be used on a larger and stronger basis. The manufacturing of new mobile linac should allow more surgeons to perform IORT and to conduct clinical trials to confirm the present indications in cancers with high local malignancy.