Although radiation therapy is the standard treatment for most intraocular malignancies, various ocular complications may occur, including radiation-induced dry eye, cataract, secondary glaucoma from neovascularization of the iris, scleral necrosis, retinopathy, and optic neuropathy. In this chapter emphasis is placed on radiation retinopathy and optic neuropathy, the two most visually significant complications of radiation therapy. While radiation complications are difficult to compare between brachytherapy, fractionated stereotactic therapy, and single fraction therapy because of differences in fraction size, total dose, dose rate, and treatment volumes, it is clear that the risk of many complications increases above certain dose thresholds. Future efforts may be directed toward limiting the exposure to healthy tissue at the time that the radiation is delivered at the time of brachytherapy and the use of preventive strategies such as anti-vascular endothelial growth factor (VEGF) agents or long-acting steroid implants to decrease the rate of radiation complications.