This work establishes the zebrafish embryo model for ionizing radiation (IR) modifier research and also evaluates the protective effect of L-alpha glycerylphosphorylcholine (GPC). Embryos were exposed to a single-fraction wholebody gamma irradiation (5, 10, 15, and 20 Gy) at different postfertilization time points and were serially assessed for viability and macro-and micromorphologic abnormalities. After toxicity evaluation, 194 lM of GPC was added for certain groups with 3-h incubation before the radiation. Nuclear factor kappa B (NF-jB) and interleukin-1b (IL-1b) expression changes were measured using quantitative real-time polymerase chain reaction. A higher sensitivity could be observed at earlier stages of the embryogenesis. The lethal dose (LD 50 ) for 6 hours postfertilization (hpf) embryos was 15 Gy and for 24 hpf was 20 Gy on day 7, respectively. GPC administration resulted in a significant improvement in both the distortion rate and survival of the 24 hpf embryos. Qualitative evaluation of the histological changes confirmed the protective effect of GPC. IL-1b and NF-jB overexpression due to 10 Gy irradiation was also reduced by GPC. GPC exhibited promising radioprotective effects in our zebrafish embryo model, decreasing the irradiationinduced morphological damage and lethality with significant reduction of IR-caused pro-inflammatory activation.