Background: Although the deep inferior epigastric artery perforator flap is the criterion standard for autologous breast reconstruction, lumbar artery perforator (LAP) and superior gluteal artery perforator (SGAP) flaps are recent trends as alternatives. The purpose of our study was to clarify differences of these flaps based on multislice CT findings of the same patient. Methods: Retrospective study was conducted on 58 patients who underwent preoperative contrast-enhanced multislice CT for breast reconstruction using deep inferior epigastric artery perforator. Of these, 32 patients' data were evaluated excluding 26 patients' data either for the lumbar or gluteal fat being outside the imaging range or for nondepiction of the vascular pedicle origin of LAP or SGAP flap. Vascular pedicle diameter, pedicle length, and subcutaneous fat thickness were measured for LAP and SGAP flaps. Results: The vascular pedicle diameter, pedicle length, and fat thickness were 2.1 (SD, 0.3) mm, 3.4 (SD, 0.4) cm, and 4.9 (SD, 1.0) cm, respectively, for LAP flaps; and 1.7 (SD, 0.2) mm, 5.6 (SD, 1.1) cm, and 2.7 (SD, 0.7) cm, respectively, for SGAP flaps. Conclusions: The LAP flaps had thicker subcutaneous fat and a larger vascular pedicle diameter, whereas the SGAP flaps had a longer vascular pedicle. As donor material for breast reconstruction, the LAP flap is indicated for cases where absolute volume is needed; otherwise, the SGAP flap is more advantageous as it facilitates vascular anastomosis with its longer vascular pedicle.