Five cases of synchronous carcinomas of uterine endometrium and ovary are reported. All uterine cancers were typical endometrial adenocarcinomas. Among the ovarian cancers, four were serous papillary cystadenocarcinomas and one was an endometrioid carcinoma. There is much controversy with respect to staging and management of such cases since these tumors may represent either two synchronously occurring primaries or a single primary with metastases. It is suggested that when each tumor is confined within the limits of its tissue of origin the tumors may be considered as two separate primaries and surgery may be less aggressive. When there is evidence that at least one tumor is spreading to adjacent tissues and organs the question of two separate primaries or one metastatic tumor becomes academic only and aggressive surgical treatment with adjuvant chemotherapy is indicated.