Peyronie’s disease (PD) is a localised fibrotic disorder of the tunica albuginea, presenting with penile curvature, pain, and erectile dysfunction. It predominantly affects men in the fifth and sixth decades and poses a significant impact on quality of life. The pathophysiology involves an aberrant wound healing response following microtrauma, leading to excessive collagen deposition and plaque formation. While oral agents and intralesional therapies offer limited benefit, especially during the acute phase, radiation therapy (RT) has shown promise in modulating inflammation, reducing pain, and potentially arresting fibrotic progression. Low-dose external beam radiation, typically administered with orthovoltage or electron beams, may be particularly beneficial when initiated early. This chapter outlines the biological basis, technical considerations, clinical outcomes, and safety profile of RT in the management of PD, and underscores its role within a multidisciplinary treatment framework.