We report an extremely rare case of a 60-year-old woman with myometrial osteosarcoma associated with bilateral papillary cystadenocarcinoma of the ovary and papillary adenocarcinoma of the cervix. The uterine osteosarcoma is the seventh case reported in the world, while it is the second case of synchronous triple primary tumors of the upper female genital tract. Clinical and pathological features of previously reported cases of uterine osteosarcoma and triple primary neoplasias of the upper female genital tract are critically reviewed.