Intraoperative radiation therapy represents a technically complex branch of radiation oncology which is undergoing intensive study. Further results of randomized Phase III trials must be available before IORT is established as an effective modality. The majority of residency training programs do not have IORT available and the use of IORT is not required for initial certification in radiation oncology. Residents could be educated in the principal concepts and the technical details of IORT and should be knowledgeable in the results of clinical trials in IORT. At the present time the leading investigators in IORT should consider offering a special research year or fellowship training in an appropriate residency training facility. If Phase III trials of IORT prove positive in a number of sites it is likely that this modality will become mainstream and then training in IORT should be required of all radiation oncology residents. Certainly there is insufficient evidence for subspecialty certification in IORT at the present time. However, one should not construe from this statement that special training in IORT is not required for its appropriate use. On the contrary, given the potential for morbidity and yet to be proven efficacy, special training in IORT should be undertaken in centers of excellence in IORT and patients treated with IORT should be entered in clinical trials whenever possible.