[en] Purpose: A retrospective analysis of 38 patients with Peyronie's disease treated with primary radiotherapy in the period of 1975-1993. Methods and Materials: Important complaints were curvature of the penis during erection for 92% of the patients, painful erection for 68%, and problems with sexual intercourse for 37.5%. Average size of all indurated plaques was 2.5 cm. The average pretreatment duration of symptoms was 9.5 months. All 38 patients were irradiated with orthovoltage radiotherapy (200 and 250 kV photons) with a total dose of 9 Gy in 5 alternating days (regimen A). Because of minimal response, 16 patients were irradiated again with another 9 Gy in 5 days and finally received 18 Gy (regimen B). Results: With regimen A, a satisfying improvement was achieved for the majority of the patients: 65% experienced less penile pain during erection, 40% reported less curvature of the penis, and 47% experienced an improvement of their sex life. With the higher dose of regimen B there was an additional improvement for a minority of the patients: 25% reported less pain during erection, 21% had less curvature, and 29% experienced an improved sex life. With regimen A, pain improvement was statistically significantly superior when compared to regimen B. For all other improvements (curvature, sexual intercourse, and induration) no dose-response relation could be demonstrated between regimen A and the higher dose regimen B. No patient experienced any radiation-induced morbidity. After evaluating regimen A and regimen B, the overall result was that 76% experienced less pain, 60% reported an improved sex life, and 48% had a diminished curvature during erection. Conclusion: From this analysis it can be concluded that the distressing symptoms of Peyronie's disease can be treated successfully with radiotherapy. Radiotherapy proves to be a safe, noninvasive treatment method without causing morbidity. Low-dose radiotherapy with only a few fractions is recommended for an effective treatment result