To evaluate the role of postoperative radiotherapy in the management of keloids. Forty-seven patients with a combined total of 60 keloids were treated with 6-MeV electron beam radiotherapy after surgical excision of the keloids. Mean daily fractions of 4 Gy (range, 3-5 Gy) were administered up to a total dose of 16 Gy (range, 12-18 Gy). The median follow-up was 70 months. Patients were asked to complete a questionnaire addressing their satisfaction with the treatment results. This self-assessment was compared with the clinical outcome. Four keloids (7%) relapsed completely, and five recurrences (8%) were classified as limited relapses. All recurrences were observed at sites of high stretch-tension. Keloid-associated symptoms, e.g. itching and pain, were improved in 81%. Hypopigmentation was observed in 29 patients (62%), a mild redness of the scar in eight patients (17%), and grade 1 telangiectasias in two patients (4%). No severe complications or secondary malignancies were observed. Self-assessments did not fully correspond to the clinical examination and recurrence status. Twelve patients were not satisfied with the treatment result, but only two of these relapsed completely. Three relapsed patients described the result of therapy as excellent or good. Postoperative electron radiotherapy is well tolerated and very effective in preventing keloid recurrence. To avoid an overestimation of cosmetic outcome, patients should be informed about achievable results before therapy starts.