OBJECTIVE To examine the long-term survival of patients with borderline ovarian carcinomas. METHODS A population-based retrospective analysis of patients registered with West Midlands Regional Cancer Registry. The files of all patients registered with ovarian carcinoma during the triennium 1985-1987 were examined and those with borderline ovarian carcinomas identified. RESULTS During the period, 1654 patients were registered, of whom 1344 had histologically confirmed ovarian carcinoma. From these 54 (4%) patients had borderline tumors--all Stage I or II. Follow-up ranged from 5 to 10 years, with only 2 patients identified where death was due to recurrent ovarian malignancy. CONCLUSIONS Epidemiological studies avoid the bias associated with hospital-based series, and enable a crude evaluation of practice standards. From this series certain areas were identified where management could be improved. Thus the information gleaned can be utilized to address such issues, and comparative studies performed in the future to assess the impact of any changes made. The series confirms the excellent prognosis associated with early stage borderline ovarian carcinomas.