Recurrences of clinical Stage I endometrial carcinoma after initial treatment are rare. They are nonetheless a serious complication, uniformly associated with poor survival outcome. Between 1969-1980, 20 patients with clinical Stage I endometrial carcinoma were treated for recurrent tumor at the time of first relapse. Nonpapillary adenocarcinoma represented 70% of the primary tumors (pure adenocarcinoma, 50%; adenosquamous, 15%, clear cell, 5%) and papillary adenocarcinoma, 30%. The most common presenting symptom was vaginal bleeding, occurring in 95% of patients. The median time to recurrence after completion of primary treatment was 9.5 mo: Adenocarcinoma relapsed at a median time of 33 mo, adenosquamous, 6 mo and papillary adenocarcinoma, 4 mo. The vagina was the site of relapse in 65% of patients, the abdomen in 20%, the pelvis in 10% and the lung in 5%. Ninety-five percent of recurrences were treated with curative intent. Complications were seen in three patients, small bowel obstruction (2 pts) and vaginal vault necrosis (1 pt); however, these patients responded effectively to conservative treatment. Minimum follow-up of 4 years was available in 18 pts (90%). Actuarial 4 yr overall and NED survival was 50%, respectively, with a median survival of 39 mo to date. There have been no deaths from further recurrence of endometrial cancer beyond 39 mo. Significant prognostic factors for 4 year survival were 1) recurrence site--vagina, 82% (9/11 pts) vs extravagina, 0% (0/7 pts; median survival: 8 mo) [p = .0001]; and 2) histologic cell type--non-papillary carcinoma, 75% (9/12 pts) vs papillary adenocarcinoma, 0% (0/6 pts; median survival: 8 mo) [p = .002]. Our review suggests that: (1) Histology and site of relapse are important prognosticators of treatment outcome; (2) Long term survival may be achieved in vaginal recurrences with aggressive local treatment; and (3) There may be a role for multimodality ovarian type treatment in overall management of recurrent papillary adenocarcinoma, a cell type that appears to exhibit a tendency towards extrapelvic spread refractory to definitive loco-regional treatment.