Rodent models of oxygen-induced retinopathy (OIR) provide important insights into the pathogenesis of human retinopathy of prematurity. Herein, we present an overview of our work with rat OIR to date. We have identified marked and consistent variations in susceptibility to OIR amongst different inbred rat strains and provide strong evidence for a genetic determinant of susceptibility to OIR. Furthermore, we have characterised differences in retinal angiogenic factor gene expression amongst different inbred rat strains exposed to cyclic hyperoxia. A key determinant of susceptibility to OIR appears to be the extent to which pro-angiogenic factor genes, such as vascular endothelial growth factor and erythropoietin, are expressed during the period of hyperoxic exposure. Those strains in which expression is relatively well maintained are less susceptible to retinopathy than are those in which expression is reduced. In addition, we identify an association between ocular pigmentation and OIR susceptibility.