Total abdominal hysterectomy (TAH) and bilateral salpingo-oophorectomy (BSO) have been performed as a standard surgical treatment for endometrial cancer. Many studies have reported on issues such as whether retroperitoneal lymphadenectomy should also be performed with TAH+BSO, to what extent lymphadenectomy should be performed when TAH+BSO is performed, and in what type of patients should lymphadenectomy be performed. These issues have been actively discussed, but there has not been any consensus. In this review article, the benefits of retroperitoneal lymphadenectomy in the initial surgical treatment for endometrial cancer will be discussed in terms of patients with pelvic lymphadenectomy and those with paraaortic (PA) lymphadenectomy. From the previous data, the establishment of TAH+BSO plus pelvic lymphadenectomy as the standard surgical treatment for endometrial cancer is thought to be reasonable. In this situation, is there benefit in performing PA lymphadenectomy? A discussion will be provided by separating the diagnostic significance from the therapeutic significance of this treatment. At present, there are no established treatments for PA-lymph node-positive patients that can be recommended more than the adjuvant therapies that are already performed at various institutions. A scientific basis that clearly indicates the therapeutic effect of PA lymphadenectomy does not exist at the present time. Despite performing thorough PA lymphadenectomy, the route of progression to extrauterine sites cannot be completely controlled. The standard surgical procedure for endometrial cancer is TAH+BSO+pelvic lymphadenectomy, which is considered necessary and sufficient. At present, the addition of PA lymphadenectomy for endometrial cancer can be regarded as only an investigated protocol.