The Box-To-X incision and closure is a novel technique for a skin-sparing mastectomy with immediate prosthetic reconstruction. The Box-To-X portal creates a 27% larger access for dissection as compared with a standard periareolar incision, while containing the entire scar within the limits of the original areola. Following nipple-areolar reconstruction and tattooing, a virtually scarless mastectomy results. Over a 54-month period, 159 skin-sparing mastectomies with immediate prosthetic reconstruction using the Box-To-X portal were performed on 98 patients. Allograft slings were used in all patients. Successful reconstruction was achieved in 93 of 98 patients (93%). Complications were observed in 23 (23%) patients. The most common complications were wound dehiscence, seroma, full-thickness necrosis along the edges of the "X," and wound infection. Removal of the implant was required in 5 patients as a result of persistent infection (5%). The low complication rate, adherence to accepted oncologic principles, and minimal scarring indicate that this technique is a sound addition to the armamentarium of both the breast oncologic surgeon and the reconstructive surgeon.