If we examine an atomic explosion as a physical phenomenon, many problems arise In the analysis of the physical picture of the explosion. The present book Is devoted to the physics of the action of gamma radiation In atomic explosions. It is known that the damaging action of an atomic explosion includes, to a consider­ able extent, the radiation sickness due to the action of gamma rays and neutrons. We shall confine ourselves only to consideration of gamma rays, since they are the main factors that determine the damaging action. The action of the gamma radiation is determined by the magnitude of the so-called dose, i.e., the absorption of gamma-radiation energy.The purpose of this book Is to estimate the dose of gamma radiation and to analyze the physical factors that influence Its m agnitude.The analysis is based on the results of the theory ofm ultiple scattering (diffusion) of gamma quanta. A new factor in the theory is the influence of the shock wave on the propogation of gamma radiation, as noted by Ya. B. Zel'dovich and the author.The calculations of the doses are referred to explosion energies of 20 megatons. This figure has no relation whatever to the present state of the art, and is chosen arbitrarily.The problems that arise in the analysis of the physical picture of the action of the gamma radiation due to atomic explo­ sion are closely related to problems involving protection against gamma radiation, encountered in the atomic industry. Therefore the book can be useful for a wide circle of scientific workers and engineers interested in problems of shielding and the dosi­ metry. The author has benefited from the interest and frommuch advice by Ya. B. Zel'dovich, and expresses him great grati­ tude. A translation of: Gamma-Izluchenie Atomnogo Vzryva. O. I. Letpunskif. Izdatel’stvo Glavnogo Upravleniya po Ispol-zovaniyu Atomnol Energii pri Sovete Ministrov S.S.S.R., Moskva, 1959.Translated by the U. S. Joint Publications Research Service, New York, a federal government organization established to service the translation and research needs of the various government department.