The North West Oncology Group is a cooperative group that has carried out several clinical trials on the treatment of ovarian carcinoma in the last 10 years. In a randomized study of advanced ovarian carcinoma patients, the combination of cisplatin plus cyclophosphamide (PC) came out as superior to cisplatin plus cyclophosphamide plus doxorubicin in terms of complete clinical and pathological response rates and 8-years progression free survival (PFS). A randomized trial showed that PAC and cyclophosphamide plus doxorubicin plus carboplatin (CAC) were equivalent in terms of objective response (OR) rates, pathologic complete response (pCR) rates, median survival (S) and median PFS. After PAC or CAC therapy, patients with pCR or minimal residual disease were included in a randomized trial comparing abdominopelvic radiotherapy (RT) versus 3 more courses of the chemotherapy they had received before. This study was stopped early because of a clear advantage in S and PFS for chemotherapy arm. Patients with macroscopic residual disease at second-look surgery and patients with progressing or relapsing disease after first line chemotherapy crossed to an alternative analogue: from PAC to carboplatin and from CAC to cisplatin. An OR was obtained in 25% of the patients of the cisplatin arm and in only 9% of the patients of carboplatin arm. Randomized clinical trials analyzing the role of intraperitoneal administration of chemotherapy and the role of biological response modifiers such as interferons in the treatment of patients with advanced epithelial ovarian carcinoma are currently ongoing.