The main prognostic factor in advanced ovarian cancer is the volume of residual disease after the initial laparotomy. Early debulking surgery after several cycles of chemotherapy, before the emergence of resistant cell lines, could improve the prognosis of patients with bulky residual disease. This study concerns patients with advanced ovarian cancer entered into three prospective trials including IV cisplatin and anthracycline-based chemotherapy, early debulking surgery after three cycles of chemotherapy in case of initial residual disease superior 2 cm and intraperitoneal consolidation chemotherapy. Among 160 patients with stage III or IV, 80 (50%) had at least a residual tumor of more than 2 cm in diameter. Early debulking surgery was effectively performed in 54 patients (67.5%), leaving 39 patients with no residue over 2 cm. Twenty-one patients had no macroscopic residual disease. The median survival of all patients with initial residual disease over 2 cm was 23 months. Patients with no macroscopic residual disease at early debulking surgery had a median survival of 44 months. Early debulking surgery appears useful in advanced ovarian cancer with bulky residual disease. The objective of this operation is to achieve no macroscopic residual lesion.