A detailed analysis of the patterns of treatment failure of ovarian malignancy may lead to a more comprehensive understanding of the natural history of the disease. A hypothesis was generated that suggests treatment failure was caused by ovarian cancer persistence and by reimplantation of tumor emboli trapped within surgically traumatized tissues. Nine ovarian cancer patients who had previously undergone standard surgical removal of the primary cancer were prospectively studied at a reoperative procedure. The operative findings at the time of primary cancer surgery and reoperative surgery were scored for the presence of tumor in 9 abdominopelvic regions and 17 abdominopelvic sites. These data were then statistically analyzed. In 7 of the 9 patients ovarian cancer recurrence was associated with an increased intraperitoneal dissemination of tumor. A mean of 3.1 regions were involved at the time of the initial surgery and 5.3 were involved at reoperation. The regions most consistently involved were those in close proximity to the primary cancer. The anatomic sites that showed a preponderance of recurrence were the rectosigmoid colon, cul-de-sac of Douglas, left paracolic gutter, vagina, and abdominal incision. Traumatized sites always showed more cancer recurrence than nontraumatized sites. The vaginal cuff and abdominal incision, sites free of cancer after hysterectomy but at high risk for tumor cell entrapment, were disproportionately common sites for cancer found at reoperation. This study shows that in this reoperative setting ovarian cancer recurrence is most common in the pelvis and the left lower part of the abdomen. The cul-de-sac of Douglas and the rectosigmoid colon are anatomic sites at extreme risk for disease progression. These are sites in which ovarian cancer implants not removed by routine hysterectomy and bilateral salpingo-oophorectomy will persist. Also, sites traumatized by surgery were disproportionately involved by cancer at reoperation. These data may be interpreted to suggest that anatomic sites with cancer persistence and with cancer implantation induced by surgical trauma are the most common sites for ovarian cancer recurrence in this select group of patients.