Aneurysmal bone cysts (ABCs) are uncommon, benign, yet locally destructive bone lesions primarily affecting children and young adults. Although surgical intervention remains the primary treatment, challenges such as recurrence and anatomical complexity often necessitate alternative approaches. Radiotherapy (RT) has emerged as a valuable option for managing inoperable, recurrent, or surgically high-risk ABCs. This chapter examines ABC pathogenesis, current treatment paradigms, and the evolving role of RT, supported by a literature review and future directions for its application in clinical practice.