It is a well established fact that women with recurrent colorectal carcinoma have a high frequency of ovarian metastases. This study was undertaken to see if microscopic metastases could be found in serial sections of ovaries removed at the time of primary operation. Of 58 patients, 4 had microscopic metastases and an additional 2 patients had macroscopic metastases. This finding, plus the risk of the development of a primary ovarian carcinoma, favors prophylactic oophorectomy in women with colorectal carcinoma.