Synchronous tumor of the fallopian tube and endometrium is an unusual co-occurrence of gynecologic malignancies. To the best of our knowledge, there have been no reports on synchronous papillary tumor of the fallopian tube and endometrium. In this report, we present the case of a patient who synchronously suffered with papillary serous adenocarcinoma of the fallopian tube and endometrium and the tumor showed characteristic frondlike projections on magnetic resonance imaging.