A 64-year-old women was operated on for acute abdomen and both appendiceal and ovarian tumors were found. Histology revealed synchronous adenocarcinoma of the appendix and serous pappillary carcinoma of the right ovary. The patient was given adjuvant chemotherapy and received six cycles of cisplatinum. Regular follow-up showed no recurrence of the two synchronous primary tumors. A rare case of synchronous primary tumors of appendiceal and ovarian origin is reported. The tumors proved to be difficult to treat requiring several combined medical therapies, including surgery, chemo- and radiotherapy.