OBJECTIVE: To evaluate retrospectively the outcomes of partial lower axillary lymph node dissection caudal to the intercostobrachial nerve in patients with clinically node-negative (N-0) breast cancer. METHODS: Numbers of dissected and metastatic nodes, overall and disease-free survival rates, postoperative complication rates, and axillary recurrence were compared between patients who underwent breast cancer surgery with partial axillary node dissection (n = 1043) and historical controls who underwent conventional dissection (n = 1084). RESULTS: The 5-year overall and disease-free survival rates were 95.6% and 89.7%, and 94.9% and 88.4%, respectively, in the partial dissection and conventional dissection groups; the differences were not significant. Mean duration of surgery (41.6 min versus 60.9 min), intraoperative blood loss (28.0 ml versus 51.3 ml), volume of lymphatic drainage at 2 weeks postoperatively (488 ml versus 836 ml), and persistent arm lymphoedema (0.0% versus 11.8%) were significantly different between the partial and conventional dissection groups, respectively. CONCLUSIONS: Partial axillary lymph node dissection was associated with similar survival rates (but lower postoperative complication rates) compared with conventional axillary dissection and is recommended in patients with N-0 breast cancer.