Background: To evaluate risk factors for upper extremity lymphedema due to breast cancer surgery. Materials and Methods: Clinical studies published on PubMed, Ovid, EMbase, and Cochrane Library from January 1996 to December 2012 were selected. Results: Twenty-five studies were identified, including 12,104 patients. Six risk factors related to the incidence of lymphedema after breast cancer treatment were detected: axillary lymph node dissection (OR=3.73, 95%CI 1.16 to 11.96), postoperative complications (OR=2.64, 95%CI 1.10 to 6.30), hypertension (OR=1.83, 95%CI 1.38 to 2.42), high body mass index (OR=1.80, 95%CI 1.30 to 2.49), chemotherapy (OR=1.38, 95%CI 1.07 to 1.79) and radiotherapy (OR=1.35, 95%CI 1.10 to 1.66). We found significant protective factors for lymphedema: pathologic T classification (OR=0.57, 95%CI 0.36 to 0.91) and stage (OR=0.60, 95%CI 0.39 to 0.93), while some factors, like age, number of positive lymph nodes, number of lymph node dissection, demonstrated no obvious correlation. Conclusions: Axillary lymph node dissection, postoperative complications, hypertension, body mass index, chemotherapy, radiotherapy are risk factors for lymphedema after breast cancer treatment. Attention should be paid to patients with risk factors to prevent the occurrence of lymphedema.