Carboplatin has proven to be effective in the treatment of patients with recurrent ovarian cancer who have responded to platinum-based first-line chemotherapy. However, thrombocytopenia is a problem in heavily pretreated patients. Paclitaxel has a so-called platelet-sparing effect, but until now it was unknown whether this effect could be obtained in heavily pretreated patients. We treated four patients with recurrent epithelial ovarian cancers who had previously undergone heavy chemotherapy. Because these patients had responded to platinum-based first-line therapy, single carboplatin administration was employed. Although satisfactory tumor marker responses were obtained, thrombocytopenia occurred. When paclitaxel was administered before the carboplatin infusion in the subsequent treatments, the thrombocytopenia became milder. It was concluded that a platelet-sparing effect was also observed in patients who had undergone heavy prior chemotherapy.