The introduction of paclitaxel/platinum combination chemotherapy and (interval) debulking surgery has significantly improved the prognosis of patients with ovarian cancer. Yet, many patients die of drug-resistant disease. Second-line chemotherapy may result in prolonged secondary remissions with alleviation of symptoms and improvement of quality of life. The response to second-line chemotherapy is strongly related to platinum sensitivity. More than 60% of platinum-sensitive patients respond to a re-challenge with platinum-containing chemotherapy. In platinum-resistant patients, on the contrary, the response rate to a re-challenge with 3-weekly platinum or any nonplatinum chemotherapy is less than 20%. The response to dose-dense weekly platinum-based regimens ranged from 48% to 64% in platinum-resistant patients. Moreover, the majority of the patients responded within 8 weeks after the start of the treatment. The progression-free survival ranged from a median of 5 months in a study using cisplatin/etoposide, to 11 months in a study with paclitaxel/carboplatin. The median survival was 11-15 months. The outpatient weekly paclitaxel/carboplatin regimen, with paclitaxel at a dose of 90 mg/m(2) and carboplatin at area under the curve 4, seems similarly effective and is better tolerated. Dose-dense weekly paclitaxel/carboplatin is an effective and well-tolerated therapy for platinum-sensitive, as well as platinum-resistant tumors. Responses to therapy are observed within 8 weeks in the majority of the patients. Whether a weekly regimen indeed is more effective than 3-weekly paclitaxel/carboplatin needs to be answered in a randomized study.