Background: Synchronous primary malignant neoplasms of the uterus are uncommon. Patients with synchronous cervical and endometrial cancers are even rarer. Materials and Methods: Presented is a case of histologically distinct cervical squamous cell carcinoma and endometrial adenocarcinoma occurring simultaneously in a 50-year-old woman with a 1-month history of postmenopausal uterine bleeding. Both simultaneous genital tract neoplasms were treated by a combination of external beam radiotherapy EBRT and californium-252 neutron brachytherapy. Results: As of March 2016, the patient has survived for nearly 4 years (complete remission). Late radiation proctitis, known to cause serious morbidity (G2), was observed half a year after the end of radiotherapy, however the signs of proctitis subsided by the use of dexamethasone. Conclusion: pelvic EBRT combined with Cf-252 neutron brachytherapy for the treatment of synchronous primary malignant neoplasms of the uterus is effective with tolerance complications.