The correlation between histological ovarian metastasis and histologic cell type, clinical stage, depth of invasion, lymph node metastasis, and menstrual activity were analyzed in 566 patients who underwent surgery for uterine cancer at the hospital of Niigata University between January, 1971 and May, 1990. Ovarian metastasis was studied in 456 patients with stage Ib or more advanced cervical cancer and 110 patients with stage Ia or more advanced endometrial cancer. The following results were obtained: 1. The incidence of ovarian metastasis of cervical cancer by histologic cell type was 18.6% (8/43) for adenocarcinoma, 6.7% (1/15) for mixed type adenocarcinoma and squamous cell carcinoma, and 0% (0/398) for squamous cell carcinoma. The metastasis rate in patients with endometrial carcinoma was 10.8% (10/93) for adenocarcinoma, but there was no metastasis of 2 squamous cell carcinoma, 13 mixed type of adenocarcinoma and squamous cell carcinoma or 2 undifferentiated carcinoma. 2. The incidence of metastasis of cervical adenocarcinoma by stage was 5.3% (1/19) for stage Ib and 29.2% (7/24) for stage II. The metastasis rate of mixed type of adenocarcinoma and squamous cell carcinoma was 0% (0/6) for stage Ib and 11.1% (1/9) for stage II. The incidence of metastasis of endometrial carcinoma was 2.1% (1/47) for stage Ia, 15.0% (3/20) for stage Ib, 15.0% (6/40) for stage II and 0% (0/3) for stage III. 3. All the patients with ovarian metastases of uterine cervical cancer had invasion to a depth of more than 2/3 of the uterine cervix, while the incidence of ovarian metastasis of endometrial carcinoma was increased with deep invasion of the uterine muscular layer, and metastasis was present even in shallow invasion.(ABSTRACT TRUNCATED AT 250 WORDS)