Many patients with advanced ovarian cancer will develop recurrent disease. For those patients who have recurrence of disease at least 6 months after initial therapy, the paclitaxel-platinum combination has been shown to be a superior treatment to platinum monotherapy. However, many patients develop clinically relevant neurotoxicity, frequently resulting in treatment discontinuation. The efficacy and safety of an alternative regimen that does not show significant neurotoxicity were evaluated by comparing gemcitabine-carboplatin with carboplatin in platinum-sensitive recurrent ovarian cancer patients in a Gynecologic Cancer InterGroup trial of the Arbeitsgemeinschaft Gynakologische Onkologie Ovarian Cancer Study Group, the National Cancer Institute of Canada Clinical Trials Group, and the European Organisation for Research and Treatment of Cancer Gynaecological Cancer Group. Participants with recurrent platinum-sensitive ovarian cancer were randomly assigned to receive either gemcitabine-carboplatin or carboplatin every 21 days. The primary objective was to compare progression-free survival (PFS) between the groups. From September 1999 to April 2002, 356 patients (178 participants received gemcitabine-carboplatin, 178 received carboplatin only) were randomized to treatment. Patients received six cycles of either gemcitabine-carboplatin or carboplatin. With a median follow-up of 17 months, median PFS was 8.6 months for gemcitabine-carboplatin (95% confidence interval [CI] 7.9-9.7 months) and 5.8 months for carboplatin (95% CI 5.2-7.1 months; hazard ratio [HR] 0.72 [95% CI 0.58-0.90; P = 0.0032]). The response rate for the gemcitabine-carboplatin group was 47.2% (95% CI 39.9-54.5%) and 30.9% for carboplatin group (95% CI 24.1-37.7%; P = 0.0016). The HR for overall survival was 0.96 (95% CI 0.75-1.23; P = 0.7349). Patients treated with gemcitabine-carboplatin reported significantly faster palliation of abdominal symptoms and a significantly improved global quality of life. Gemcitabine-carboplatin treatment significantly improves the PFS of patients with platinum-sensitive recurrent ovarian cancer.