Intraoperative radiotherapy (IORT) of the breast is the administration of a single fraction of radiation to the tumor bed while shielding low risk and uninvolved tissues from the effects of radiation. The TARGIT A and ELIOT trials demonstrate efficacy of IORT when administered at the time of lumpectomy to post-menopausal women with low to intermediate grade, lymph node negative, invasive ductal carcinoma, consistent with international guidelines defining suitable candidates for accelerated partial breast radiotherapy. J. Surg. Oncol. 2014 110:68–74. © 2014 Wiley Periodicals, Inc.