PURPOSE: A subcutaneous mastectomy has been proven to be oncologically safe for early breast cancer. Although a subcutaneous mastectomy and reconstruction are well established, most incisions are made directly on the breast. To improve the cosmetic outcome, an endoscopic subcutaneous mastectomy and immediate reconstruction was undertaken, which can be performed through minimal axillary and periareolar semicircular incisions. METHODS: Between October 2002 and December 2003, 9 patients with early breast cancer, whose tumors were less than 4 cm in size and more than 2 cm-apart from the nipple-areolar complex, and who were clinically node negative without invasion to skin and pectoralis muscle, underwent 10 endoscopic subcutaneous mastectomies with immediate reconstruction employing saline bag implants. Firstly, an endoscopic dye-guided sentinel node biopsy was performed through a low transverse axillary incision lateral to the pectoralis major. A subpectoral pocket was gently created under the view of endoscopic monitor by Vein Harvest. A periareolar semicircular incision was made to create the skin flap using Visiport and PowerStar Scissors. Frozen section biopsies were performed to rule out tumor invasion to the resection margin. After resection of the entire breast tissue, a saline bag prosthesis was inserted. The patients and tumor characteristics, operation times, amounts of bleeding, and cosmetic results were evaluated. RESULT: The mean patient age was 45 years (25~55). The mean tumor size was 2.5 cm, ranging from 0.7 to 5.0cm. The average operation time was 112 minutes (80~150). The mean amounts of operative bleeding was 232 ml. There was one case of transient necrosis of the nipple-areolar complex. An early implant removal was performed in one patient due to a suspected microperforation. Excellent or good cosmetic results were obtained in 8 patients (88.8%). CONCLUSION: An endoscopic subcutaneous mastectomy with immediate reconstruction, is a new technique that can minimize the direct operation scar on the breast skin following a classic operation. In properly selected cases, our results show maximized cosmetic satisfaction of breast cancer patients, so offers a promising alternative to a classic subcutaneous mastectomy with immediate reconstruction.