Specimen radiography is an important part of breast conservation surgery for ductal carcinoma in situ (DCIS). The objective of this study was to determine whether mastectomy specimen radiography could help in obtaining negative resection margins in patients with DCIS undergoing skin-sparing mastectomy (SSM) with immediate breast reconstruction (IBR). Of 95 patients treated at our institution with SSM and IBR for DCIS, 35 had specimen radiography. The mastectomy specimen was first examined grossly and then inked, serially sectioned, and sent for radiographic assessment. Tissue slices containing calcifications were identified for pathologic evaluation. Additional tissue was excised if tumor was found near the inked margins or if calcifications were found near the radiographic margins. Of the 35 patients who had specimen radiography, the radiographic margins were free of calcifications in 30 patients (86%); of these patients, the margins on the final histologic examination were free of tumor in 27 and within 1 mm in 3. The other five patients (14%) had calcifications close to the radiographic margin; four underwent an intraoperative re-excision, but the margin for one of those four patients was still positive on final histologic examination. Margins were found to be negative by both mastectomy specimen radiography and histology in 77% of the patients. Of the 95 patients with DCIS, three patients (3%), none of whom had specimen radiography, developed local recurrences. One of these was successfully re-treated, one died as a result of synchronous distant metastases, and one was lost to follow-up. At a median follow-up time of 3.7 years, 93 patients (98%) were alive and free of disease. Intraoperative radiography of mastectomy specimens may be useful for assessing margin status and for identifying the location of microcalcifications within tissue slices.