Peripheral retinal neovascularization (i.e., new vessel growth peripheral to the major vascular arcades) may be secondary to a wide variety of ocular and systemic diseases. Vascular and inflammatory diseases in particular may cause peripheral neovascularization. Following a brief review of ocular angiogenesis, the various clinical entities that can cause peripheral retinal neovascularization are described. The diagnostic workup of a patient with peripheral proliferative retinopathy is outlined and techniques of treatment of the neovascularization (including feeder vessel technique, cryopexy, and panretinal photocoagulation) are discussed.