Abstract Objective The aim of this study was to determine the incidence rate of lower-extremity lymphedema after systematic lymphadenectomy in patients with uterine corpus malignancies and to elucidate risk factors for this type of lymphedema. Methods A retrospective chart review was carried out for all patients with uterine corpus malignant tumor managed at Hokkaido Cancer Center between 1991 and 2007. Patients who did not undergo lymphadenectomy as a treatment or died of cancer/intercurrent disease were excluded from this study. All living patients included in this study had hysterectomy, bilateral salpingo-oophorectomy and lymphadenectomy and their medical records were reviewed. We identified patients with postoperative lower-extremity lymphedema (POLEL). Logistic regression analysis was used to select the risk factors for POLEL. Results Of 286 patients evaluated, 103 (37.8%) had POLEL. Multivariate analysis confirmed that adjuvant radiation therapy (OR = 5.2, 95% CI = 2.1–12.7), resection of more than 31 lymph nodes (OR = 2.6, 95% CI = 1.4–4.9), and removal of circumflex iliac nodes to the distal external iliac nodes (CINDEIN) (OR = 6.1, 95% CI = 1.3–28.2) were independent risk factors for POLEL. Conclusion Adjuvant radiation therapy should be avoided in patients who undergo systematic lymphadenectomy if an alternative postoperative strategy is possible. Although reducing the number of resected lymph nodes is not appropriate from a therapeutical point of view, elimination of CINDEIN dissection may be helpful in reducing the incidence of POLEL. The clinical significance of CINDEIN dissection needs to be investigated by a randomized controlled trial.