Eighty-six patients with pathologic Stage I or occult Stage II carcinoma of the endometrium and myometrial invasion and/or Grade 2 or Grade 3 histologic condition received whole-pelvis external radiation therapy (RT) after extrafascial total abdominal hysterectomy and bilateral salpingo-oophorectomy. Twenty-one patients received 4250 cGy in 25 daily fractions for 5 weeks (Group 1), 28 received 4500 cGy in 25 daily fractions for 5 weeks (Group 2), and 37 received 5100 cGy in 30 daily fractions for 6 weeks (Group 3). Seventeen patients had intravaginal brachytherapy after whole-pelvis RT. Local recurrence developed in two patients (2.3%) (one in Group 1 and one in Group 2). Statistical analysis showed that the depth of myometrial invasion significantly influenced survival (P = 0.016). Tumor grade, pathologic stage, whole-pelvis radiation dose, and the use of brachytherapy did not influence survival. Complications occurred in 9.5% of patients in Group 1, 24.7% in Group 2, and 40.5% in Group 3. Three patients who received brachytherapy had rectal injuries. The authors conclude that 4250 cGy in 25 fractions for 5 weeks of whole-pelvis RT appears to induce fewer complications than higher doses, and may be sufficient to prevent local recurrence in most patients who require adjuvant RT. A clinical trial is needed to determine the optimum dose-time-fractionation regimen.