To investigate the role of radiotherapy for stage I epithelial ovarian carcinoma, the results in 91 patients treated from 1970-1989 were retrospectively analysed. There were 60 patients treated by operation combined with chemotherapy, 31 patients by operation combined with chemotherapy and radiotherapy. Patients in both groups were comparable with regard to age, clinical stage, histology grade, type of operation and chemotherapeutic regimen. The 5-year actuarial survival rate was 78.3% for those receiving additional radiotherapy and 72.4% for those without additional radiotherapy. The recurrence rate was 32.2% with a median recurrence time of 34 months in the former group while 60.6% and 18.6% months for the latter. Radiotherapy did not confer survival advantage in the treatment of stage I ovarian cancer, but it could decrease recurrence rate and delay onset of recurrence.