This study aimed to assess the prognostic significance of para-aortic lymphadenectomy (PALX) and para-aortic lymph node metastasis in endometrial cancer (EC) patients at risk of post-operative recurrence. Japanese Gynecologic Oncology Group (JGOG) 2043 was a randomized controlled trial assessing the efficacy of adjuvant chemotherapy in EC patients at risk for post-operative recurrence. A retrospective analysis included patients who underwent pelvic lymphadenectomy (PLX) alone or both PLX and PALX in JGOG2043. Data on positive lymph nodes and other clinicopathological risk factors were collected. PLX and PALX were performed on 402 patients, while PLX alone was conducted on 250 patients. Evaluating the effect of PALX on survival was challenging through a comparison of the outcomes of the 2 cohorts since PALX was predominantly administered to higher-risk patients. Patients with 2 or more metastases in para-aortic nodes exhibited significantly poorer overall survival than those with no or 1 metastasis, respectively (p<0.001, p=0.031). Multivariate analysis revealed that 2 or more metastases in para-aortic nodes is independent risk factors for disease-free survival (hazard ratio [HR]=1.72; 95% confidence interval [CI]=1.10-2.72; p=0.019) and are marginally significant for overall survival (HR=1.58; 95% CI=0.92-2.72; p=0.096) compared to no or a single metastasis. The clinical relevance of PALX was challenging to evaluate in the JGOG2043 cohort; however, the presence of 2 or more para-aortic node metastases was identified as an independent unfavorable prognostic factor in EC patients at risk of recurrence.