The purpose of this study was to evaluate the efficacy of adjuvant 32P for patients with high-risk, early-stage ovarian carcinoma. Twenty-five patients underwent apparent complete resection followed by 32P (15 mCi) at the University of Florida between 1976 and 1993. Minimum and median follow-up times were 3 and 8 years, respectively. The rate of local control at 10 years was 83%. Four of the 5 patients who experienced recurrent disease had a component of intra-abdominal disease at the time of relapse. The absolute and cause-specific survival rates at 10 years were 68% and 82%, respectively. There were no severe acute complications. Five patients experienced significant late complications, including chronic abdominal cramping that was treated conservatively (3 patients) and small bowel obstruction necessitating surgical intervention (2 patients). Adjuvant 32P results in disease control and survival rates that are similar to those observed after adjuvant chemotherapy. However, the risk of late complications, particularly small bowel obstruction, is higher.