We investigated the pattern and frequency of ovarian metastases in patients with primary gastrointestinal malignancies and evaluated the response to surgery, chemotherapy and in three cases radiotherapy. The literature reports that this group of patients have a poor prognosis, but no report has specifically addressed the response to chemotherapy. Using a database which is generated prospectively, we analysed 51 patients with primary gastrointestinal malignancies and ovarian metastases. All patients received chemotherapy but only 36 were evaluable for response; five had adjuvant treatment and ten had non-measurable disease. Seventeen patients had surgical oophorectomy and three patients received radiotherapy. The overall response rate to chemotherapy was 22%; eight partial responses and no complete responses. When stratified according to site of response, 11 (31%) patients had a partial response at sites of extraovarian metastases and only five (14%) had a partial response in the ovaries. Seven patients with primary colorectal cancer had a differential response in favour of extraovarian sites. The median survival was 9 months for the 51 patients. Three premenopausal women with resected gastric carcinoma received adjuvant chemotherapy and relapsed only in the ovaries. In primary colorectal tumours the response of ovarian metastases to chemotherapy is less than that for other sites. Therefore, the ovary may be a sanctuary site for metastases which has important implications for adjuvant chemotherapy in women. These women could be followed up regularly by transvaginal ultrasonography to detect such metastases at an early stage when they would be amenable to surgical resection. Surgery should be considered for selected patients who develop metachronous metastases, as patients may be rendered disease free for several months.