Objective. A phase II study was conducted to evaluate the role of adjuvant intraperitoneal radioactive phosphorus (~(32)P) and vaginal brachytherapy in patients with uterine papillary serous carcinoma (UPSC) and clear cell carcinoma (CCC), after complete surgical staging. Methods. Patients were required to have undergone complete surgical staging including maximal surgical resection. Residual ≤ 3 mm intraperitoneal disease, and pelvic and para- aortic lymph node dissection with negative nodes, were required. A dose of 15 mCi of intraperitoneal 32P was administered within 8 weeks of surgery. Vaginal brachytherapy was delivered using either high dose rate, total dose of 2100 cGy in 3 fractions (700 cGy per fraction prescribed to 0.5 cm depth from the vaginal surface) or low dose rate to 6500 cGy (prescribed to the vaginal surface) in 1- 2 fractions. Results. For the 21 evaluable patients, distribution by FIGO stage was as follows: Stages I- IIB (17), Stages III- IV (4). The median follow- up was 39.6 months (range: 5- 63 months). No patients experienced grade 2- 4 complications from their adjuvant therapy. Five patients suffered a recurrence: intraperitoneal [n = 2], distal vaginal [n = 2], and one at the surgical scar. Following the 2 distal vagina recurrences early in the trial, the entire length of the vagina was treated with intracavitary brachytherapy. No additional vaginal recurrences were observed. The two- year overall survival, cause- specific survival, and disease- free survival for the entire series were 89.2% , 89.2% , and 79.7% , respectively. Conclusions. Adjuvant therapy for UPSC and CCC with intraperitoneal 32P and vaginal brachytherapy after comprehensive surgical staging is feasible, well tolerated, and warrants further study on a larger scale. Objective. A phase II study was conducted to evaluate the role of adjuvant intraperitoneal radioactive phosphorus (~ (32) P) and vaginal brachytherapy in patients with uterine papillary serous carcinoma (UPSC) and clear cell carcinoma (CCC), after complete surgical staging. Methods. Patients were required to have undergone complete surgical staging including maximal surgical resection. Residual ≤ 3 mm intraperitoneal disease, and pelvic and para- aortic lymph node dissection with negative nodes, were required. A dose of 15 mCi of intraperitoneal 32P was administered within 8 weeks of surgery. Vaginal brachytherapy was delivered using either high dose rate, total dose of 2100 cGy in 3 fractions (700 cGy per fraction prescribed to 0.5 cm depth from the vaginal surface) or low dose rate to 6500 cGy (prescribed to the vaginal Surfaces in 1- 2 fractions. Results. For the 21 evaluable patients, distribution by FIGO stage was as follows: Stages I- IIB (17), Stages III- IV (4). The median folds Five patients suffered a recurrence: intraperitoneal [n = 2], distal vaginal [n = 2], and one at the surgical scar. Following the 2 distal vagina recurrences early in the trial, the entire length of the vagina was treated with intracavitary brachytherapy. No additional vaginal recurrences were observed. The two-year overall survival, cause-specific survival, and disease Conclusions. Adjuvant therapy for UPSC and CCC with intraperitoneal 32P and vaginal brachytherapy after comprehensive surgical staging is feasible, well tolerated, and warrants further study on a - free survival for the entire series were 89.2%, 89.2%, and 79.7% larger scale