BACKGROUND: Ipsilateral supraclavicular lymph node metastasis (ISLM) with breast cancer patients has always been a hard problem for breast surgery. It is generally believed that radiotherapy can benefit the survival of patients, but whether local surgical resection is needed or not is controversial. The study aims to compare the efficacy between supraclavicular lymph node (SLN) dissection combined with radiotherapy and radiotherapy alone in the treatment of breast cancer with ISLM. METHODS: A retrospective analysis was performed using 122 cases of breast cancer with ISLM but without distant metastasis. Among them, 14 cases were eliminated due to insufficient data. The 108 remaining cases were divided into 2 groups based on different treatment proposals for metastatic SLNs. The groups were dissection plus radiotherapy (surgery group), and simple radiotherapy (radiotherapy group). RESULTS: For the 108 patients, the overall 5-year disease-free survival (DFS) and overall survival (OS) rates were 30.6% and 67.8%, respectively. In the surgery group, distant metastases occurred in 41 patients, and the 5-year DFS was 34.3%; in the radiotherapy group, 18 patients had distant metastases, and the 5-year DFS was 26.1%; the difference was not statistically significant (P>0.05). In the surgery group, 11 patients died, and the 5-year OS rate was 67.9%; in the radiotherapy group, 6 patients died, and the 5-year OS rate was 67.5%; the difference was not statistically significant (P>0.05). CONCLUSIONS: The dissection of SLN combined with radiotherapy and radiotherapy alone had similar effects on the survival rates in breast cancer patients with ISLM. The local control in the surgery group was better than that in the radiotherapy group. The status of estrogen receptors (ER) and the number of axillary lymph node metastases were independent influencing factors of DFS. The ER status is an independent factor affecting the OS rate of patients.