The ovarian remnant syndrome, a complication of bilateral salpingo-oophorectomy, is progressively receiving more attention in the gynecological surgery literature. The syndrome is manifested by pelvic pain and a palpable or sonographic finding of a pelvic mass. However, in rare cases, patients can present with large masses and radiographic suggestion of malignancy. We present the case of a 76-year-old white female, 23 months after bilateral salpino-oophorectomy at the same institution, complaining of 3.5 months of right flank and abdominal pain. Clinical and radiological evidence of a right ovarian remnant was discovered. Subsequent laparoscopic resection was consistent with a well-encapsulated mucinous adenocarcinoma in a right ovarian remnant. Curiously, this patient had no history of endometriosis, dense pelvic adhesions, pelvic inflammatory disease, or difficulty encountered during the original hysterectomy. This is the seventh published case report in the international literature about carcinoma developing in an ovarian remnant. However, this case differs in that the patient had no preexisting gynecologic conditions at the time of hysterectomy and bilateral salpingo-oophorectomy to account for residual ovarian tissue. Additionally, the oophorectomy was performed vaginally, in contrast to multiple previous case reports.