Caloric restriction mimicked by administration of 2-deoxy-D-glucose (2DG) has been shown to protect cerebral neurons against ischemia and excitotoxicity. This study examined the protective effects of pretreatment with 2DG on retinal neurons in N-methyl-D-aspartate (NMDA) excitotoxicity in rats. There was a significantly reduced number of TUNEL-labeled cells in the retinal ganglion cell layer 18 h after intravitreal injection of NMDA with 2DG pretreatment. At 7 days after NMDA, 2DG pretreatment significantly preserved neurons in the retinal ganglion cell layer and reduced immunoreactivity of glial fibrillary acidic proteins in retinas. Our findings demonstrate that caloric restriction mimicked by 2DG protects retinas from NMDA excitotoxicity.