Background : The indications for and the optimal mode of adjuvant therapy in surgically operated endometrial cancer patients have not yet been established. We studied the indications for the postoperative treatment of endometrial carcinoma patients based on their surgical stages (FIGO, 1988) . Methods : We retrospectively restaged the cases of 178 endometrial carcinoma patients who underwent hysterectomy with pelvic lymphadenectomy between 1965 and 1992 and who were followed-up longer than 3 years. The patients were subdivided into low- and high-risk groups, and we investigated the relation between their postoperative treatment and recurrence rates. Postoperative treatment was divided into the three groups of no/incomplete, external whole-pelvic irradiation (EWPI) and chemotherapy. Results : The 79 patients in Stage Ia or Ib had no/incomplete postoperative treatment, but only 1 (1.3%) had a recurrence. Four Stage IIa patients had no recurrence and all 3 low-risk patients had no postoperative treatment. Of the 5 Stage IIb, low-risk patients, 1 of the no postoperativetreatment group had a recurrence. The recurrence rate among the Stage IIb patients of the high-risk group was 40% (2/5) in the incomplete postoperative treatment group. The six Stage IIIa patients with EWPI. had no recurrence. In contrast, 14 of the 15 Stage IIIb and IIIc patients underwent postoperative EWPI, and 11 of them (78.6%) had a recurrence including 8 (81.8%) with a recurrence in distant regions. Conclusion : Postoperative treatment may be well omitted for many patients at Stage Ia or Ib and the low-risk group at Stage IIa based on surgical staging criteria. Patients in other surgical stages seemed to require to identify best postoperative treatment , but further randomized prospective studies will be required to identift the best mode of treatment