Objective: In this study, we evaluated the effect of supraclavicular lymph node dissection in breast cancer patients who presented with ipsilateral supraclavicular lymph node metastasis (ISLM) without distant metastasis. Methods: A total of 90 patients with synchronous ISLM without distant metastasis between 2000 and 2009 were retrospectively analyzed. Patients were retrospectively divided into two groups, namely supraclavicular lymph node dissection group(34 patients) and non-dissection group(56 patients), according to whether they underwentsupraclavicular lymph node dissection or not.The Kaplan-Meier method was applied to analyze the locoregional relapse free survival (LRFS) and overall survival(OS). Results: Median follow-upwas 85 months(range, 6 to 11 months). Local recurrence in 32 cases, 47 cases of distant metastasis, of which 25 patients were accompanied by both locoregional relapse and distant metastasis. Of the 32 patients with locoregional relapse, 11 patients were in the lymph node dissection group and 21 patients in the control group. Of the 47 patients with distant metastases, 17 were treated with lymph node dissection, 30 in the control group. Thirty-two patients died in the whole group and 16 patients underwentlymph node dissection and 16 patients didn't. There was no significant difference between the rate of 5-year LRFS and 5-year OS (P=0.359, P=0.246). For patients of ER negative, the 5-year loco-regional relapse free survival rates were 63.7% and 43.3% in supraclavicular lymph node dissection group and control group, respectively. The 5-year overall survival rates were 52.1% and 52.3%, respectively, and there were no statistically significant differences (P=0.118, P=0.951). For patients of PR negative, the 5-yearloco-regional relapse free rates were 59.8% and 46.2%, respectively, and the 5-year overall survival rates were 50.6% and 43.2%, respectively, and there was no significant difference between the two groups (P=0.317, P=0.973). The 5-year recurrence-free survival rates of human epidermal growth factor receptor 2 (HER2)-positive patients were 61.2% and 48.0%(P=0.634), respectively, and the 5-year overall survival rates were 37.2% and 65.4%(P=0.032). Forty-seven patients suffered distant metastases and the 5-year metastases free survival rates were 37.3% and 38.5% in supraclavicular lymph node dissection group and control group, respectively. Conclusion: Supraclavicular lymph node dissection maybe an effective approach to improve the loco-regional control for the patients with ISLM, especially for ER negative and PR negative subtypes, but it might has adverseeffects for the patients with negative HER2 status.