From 1958 to 1967, a prospective randomized trial was conducted in 189 women with stage I, group I endometrial adenocarcinoma, comparing treatment by hysterectomy alone, preoperative uterine radium followed by hysterectomy, and hysterectomy and postoperative vaginal radium. All women have been followed for a minimum of 10 years. The actuarial survival rate at 5 years for all patients was 94.5% and at 10 years, 92.6%, with no statistical significance among the 3 treatment groups. There was also no statistical significance in survival rate in relation to size of uterine or myometrial invasion. There was a statistically significant difference in survival between grade I and grade III lesions (P< 0.01) and between grade II and grade III lesions (P< 0.05).