Pterygium is a common ophthalmologic condition characterized by fibrovascular proliferation of the conjunctiva that may extend over the cornea, leading to visual disturbances, cosmetic concerns, and discomfort. Its etiology is multifactorial, with ultraviolet radiation and environmental exposure being prominent contributors. Surgical excision remains the mainstay of treatment; however, high recurrence rates have necessitated adjunctive therapies. Among these, radiation therapy, particularly beta-irradiation using Strontium-90, has demonstrated promising results in reducing recurrence and improving patient outcomes. This chapter elaborates on the background, pathogenesis, therapeutic rationale, radiation techniques, toxicity profiles, and future perspectives in the use of radiation therapy for managing pterygium. A comprehensive review of literature and case studies is also presented to highlight the current evidence and clinical applicability.