Seventeen multiple primary cancers including 16 double cancers and one triple cancer were found in 316 patients with gynecologic malignancies who were treated in our department from 1984 to 1988. All pathologic slides but one were reviewed, and cases with possible metastasis or recurrence were not included in this study. The incidence of multiple primary cancers in gynecologic malignancies was 5.4%. Multiple primary cancers were encountered in 4.4% of 205 cervical cancers (including carcinoma in situ), 15.2% of 33 endometrial cancers, and 8.6% of 58 ovarian cancers (including low potential malignancy), respectively. The most frequent sites of other cancers were seen in the large intestine and rectum (5/17), breast (4/17), and gynecologic organs (3/17). Higher incidences were seen in our study that in those in domestic literature. This is probably because detailed anamnesis and gastrointestinal series were obtained in most gynecologic malignancies (especially in endometrial or ovarian cancer).