Objective: To compare the clinical efficacies between endoscopic and traditional open approaches for intercostobrachial nerve preservation during axillary dissection for breast cancer. Methods: Forty-six patients with stage I or II breast cancer, who were scheduled to undergo modified radical mastectomy with intercostobrachial nerve preservation, were randomly designated to either endoscopic group (n=21) or traditional group (n=25). Sensory functions in inner aspect of upper arm and armpit were examined after the operation. Results: In endoscopic group and traditional group, the intercostobrachial nerves were successfully preserved in 20 cases (20/21) and 23 cases (23/25) respectively, and there was no statistical difference in the successful rate between the two groups (P=0.658). The time taken for axillary dissection was prolonged but the volume of blood loss during axillary dissection and postoperative complications in endoscopic group were significantly reduced compared with traditional group (P<0.001, P=0.029). The entire group was followed up for 2 to 20 months with average of 16 months after operation; no recurrence occurred in any of the patients and no abnormal subjective sensations were observed in any of the patients with intercostobrachial nerve preservation. Conclusion: Preservation of intercostobrachial nerve is feasible in endoscopic axillary dissection, which also has the advantages of reducing blood loss and postoperative complications.