This randomized, open label, phase III clinical trial (1988–1992) compared the efficacy and safety of a dose-dense regimen of single-agent cisplatin with a standard 3-weekly schedule in first-line chemotherapy for advanced epithelial ovarian cancer. Two hundred eighty-five patients were randomly assigned to the experimental dose-dense arm (cisplatin 50 mg/m weekly × nine cycles) or to the control (standard treatment) arm (cisplatin 75 mg/m, administered on day 1 every 21 days × six cycles). The primary outcome was progression-free survival (PFS). Secondary outcomes were overall survival (OS), overall response to chemotherapy, and toxicity. Toxicity and response to treatment were compared with the χ test using trend or exact correction. PFS and OS were estimated by Kaplan–Meier analyses and treatment hazard ratios (HRs) with the Cox proportional hazards model. All statistical tests were two-sided. After a median follow-up of 16.8 years, no differences were observed between the two treatments in PFS (experimental arm: 17.2 months; control arm: 18.1 months; HR = 1.08, 95% confidence interval [CI] = 0.83 to 1.40; P = .57) and in OS (experimental arm: 35 months; control arm: 32 months; HR = 0.97, 95% CI = 0.75 to 1.26; P = .97). Thus, increasing dose intensity of cisplatin does not improve PFS or OS compared with standard chemotherapy.