Objectives To evaluate the rate of survival and recurrence related to the introduction of pelvic lymphadenectomy in Danish high-risk endometrial cancer patients. Study design Data on 713 high-risk patients defined as grade 3 with >50% myometrial invasion or serous/clear/undifferentiated carcinomas stage I-IV endometrial cancer patients diagnosed from 2005 to 2012 were retrieved from the Danish Gynecological Cancer Database. Of these, 305 were high-risk stage I. Five year Kaplan-Meier survival estimates and actuarial recurrence rates were calculated, and adjusted Cox used for comparison. Findings were compared with earlier Danish results. Results Lymphadenectomy in 390 radically operated high-risk patients resulted in upstaging of 31 patients from stage I to IIIC and 19 patients from stage II to IIIC corresponding to 12.8%. Upstaging from stage I to IIIC had a cancer-specific survival of 77%, almost comparable to lymph node-negative high-risk stage I patients (81%). Lymphadenectomy patients had a significant higher overall survival as compared with non-lymph node resected for all patients, but not for stage I patients. Lymphadenectomy, however, did not significantly affect cancer-specific survival, progression-free survival, recurrence rate or risk of local, distant, or lymph node recurrence. When the survival of high-risk stage I patients was compared with earlier Danish results, a small improvement in overall survival (7%) and cancer-specificsurvival (8%) was demonstrated. Conclusion Only a small number of high-risk patients were upstaged from stage I to III due to lymphadenectomy. These patients showed a surprisingly good survival possibly due to correct stage identification and subsequent relevant adjuvant therapy. However, even though introduction of lymphadenectomy in the Danish high-risk population seems to increase overall survival, no significant change in cancer-specific survival, progression-free survival or recurrence patterns was demonstrated.