The purpose of the current review was to examine whether systematic lymphadenectomy is safe and effective for treating early-stage endometrial cancer. PubMed, Embase, the Cochrane Library and the China National Knowledge Infrastructure databases were systematically searched during April 2014 to identify studies comparing the use of systematic lymphadenectomy and no systematic lymphadenectomy in parallel for the treatment of early-stage endometrial cancer. A total of 13 eligible studies involving 51,155 patients were included in this review. The median overall survival (OS) rate at 5 years following lymphadenectomy was 90% (range, 73.1–98.3%) for patients undergoing the systematic procedure and 88.2% (range, 68–98.4%) for patients not undergoing the systematic procedure. For the two types of lymphadenectomy, OS has tended to improve over the last 20 years. The combined rate of disease-free and progression-free survival was higher in patients who underwent systematic lymphadenectomy, and the recurrence rate was lower. In particular, systematic lymphadenectomy was associated with markedly higher OS than the non-systematic procedure for patients with intermediate- and high-risk endometrial cancer when ≥11 lymph nodes were removed. Systematic lymphadenectomy demonstrates clinical benefit in patients with early-stage endometrial cancer and should thus be a standard treatment option. In conclusion, systematic lymphadenectomy leads to higher OS than no systematic lymphadenectomy in intermediate- and high-risk patients with early-stage endometrial cancer, particularly when the procedure removes ≥11 lymph nodes.