A study of data from 318 cases of uterine sarcoma presenting during a 10-year period (1967-1976) is reported. All but 6 of the patients had at least a 5-year follow-up (98% 5-year follow-up). Overall 5-year survival was 31%, with the major prognostic indicator being tumour stage. Despite the tendency for mixed mesodermal tumours to present in older women with more advanced disease, survival was not statistically different to those patients with leiomyosarcomas. Thus, the propensity for tumour dissemination in leiomyosarcomas should not be underestimated. Leiomyosarcomas are less likely to present with abnormal symptoms than are other sarcomas, and their occurrence as an incidental finding on histological examination underlines the need for an adequate inspection of the intra-abdominal contents at hysterectomy. The tendency to treat all sarcomas as if they were endometrial tumours may be fallacious, and an alternative classification (such as the TNM system) may be required. Recurrence of tumour tended to be at distant sites (distant:pelvic recurrence rate 3:1). Adjuvant radiotherapy is unlikely to alter distant disease foci, and thus the development of combination chemotherapeutic regimens using agents which have shown to result in tumour response seem warranted. Such trials will need to be organised on a multicentre basis to attain statistically evaluable numbers of patients.