There is no established treatment for appendiceal mucinous adenocarcinoma. When this condition is complicated by pseudomyxoma peritonei(PMP), multidisciplinary treatment is often administered. A 40-year-old woman was diagnosed with right ovarian cancer for which laparotomy was performed. At the time of laparotomy, we considered the tumor to be an appendiceal carcinoma infiltrating the right ovary and performed ileocecal resection with lymph node dissection(D3)and right salpingo-oophorectomy. The pathological diagnosis was stage pT3, pN0, pM0, pStage Ⅱ mucinous adenocarcinoma of the appendix. Fourteen months later, the patient underwent abdominal total hysterectomy and left salpingo-oophorectomy because a CT scan suggested recurrence in the uterus, left fallopian tube, and ovary. Seventeen months after the second operation, despite adjuvant chemotherapy, CT revealed a peritoneal nodule in the pelvic cavity. Therefore, we administered chemotherapy comprising 5 lines for 32 months, which resulted in failure. CT showed an enlarged tumor and ascites and the patient became terminally ill. We repeatedly performed cytoreduction surgery and intraperitoneal chemotherapy, which improved her QOL. One year after discharge, abdominal CT showing an abdominal wall and intraperitoneal mass. We performed again cytoreduction surgery and intraperitoneal chemotherapy. Her postoperative course is good and she is currently an outpatient.