In advanced endometrial cancer, the importance of peritoneal cytology and optimal surgical cytoreduction remain subjects of discussion. We evaluated our clinical experience of 67 patients with FIGO stage III and IV endometrial cancer treated in the Erasmus Medical Centre in Rotterdam over a 20-year period with an emphasis on stage IIIA disease based on positive cytology only and optimal cytoreduction. Lymphadenectomy was not routinely performed and peritoneal cytology was examined in 74% of the patients. Stage IIIA disease was found in 33 patients, 10 of whom had positive cytology only. Analysis showed that incidence of recurrence and survival rates of patients with stage IIIA disease based on positive cytology only were comparable with stage IIIA disease based on other factors. In 50 patients, it was possible to remove all macroscopic tumor, whereas in 17 patients, an optimal cytoreduction was not achievable. The 2- and 5-year survival rates after optimal cytoreduction were 82.2% and 65.6%; where this could not be achieved, these figures were 50.8% and 40.6%. In advanced endometrial cancer patients, positive peritoneal cytology seems an important prognostic factor in stage IIIA disease if lymph node status is unknown. Survival is improved if optimal surgical cytoreduction is achievable.