We report the clinical management and outcome of 11 patients with a histological diagnosis of mixed mullerian tumour of gynaecological origin who were treated at Weston Park Hospital, Sheffield during the period 1991 to 1996. Case note review provided the data on the patients, their disease and the treatment given. In six patients, the primary site was the ovary and in four it was the uterus; in the remaining patient, the tissue of primary origin was uncertain. The median age at diagnosis was 53 years (range 48–84). Seven patients had heterologous tumour histology. All but one underwent surgical removal or debulking of disease. Seven patients were treated with platinum-based chemotherapy. There were four complete responders and three partial responders. The median survival was 18 months. Three patients remain alive, two of them disease-free.Mixed mullerian tumours are initially chemosensitive but have an aggressive clinical course, typically with early relapse after treatment and a poor long- term prognosis. Collaborative Phase III studies are required to improve the management of this uncommon cancer.