A big part of our cultural heritage is made from natural materials which are very sensitive to surrounding conditions and thus get easily infected; therefore it is necessary to protect such objects. Disinfection through ionizing radiation has been proven to be very effective, because it is based on electromagnetic radiation from radioactive 60Co, which causes chemical damage of DNA molecules of all biological pollutants. Contrary to all other methods gamma rays are highly penetrating acting on all pests present in all parts of a treated object not only on its surface and they act on pests in their whole life cycles; from spores to grown pests. Among all the advantages of the radiation technology it needs to be outlined that it is harmless for humans and damage of the material is minimal, when using optimal conditions. In the process of irradiating an object of cultural heritage the most important parameter to pay special attention to is the radiation dose. The used dose depends on how contaminated the object is, the desired reduction of pests and their radio sensitivity, as well as type of material and its condition. It is necessary to apply the smallest possible dose for deactivation of biological contaminants, which should also be smaller than the dose that would damage the material or change its appearance. In this work, we investigated the influence of radiation on natural leather which is used for restoring leather book covers using gama rays in the Radiation Chemistry and Dosimetry Laboratory at Ruđer Bošković Institute. With this research, we wanted to investigate the effect ionizing radiation has on natural leather, treated and non-treated. The main objective was to determine can radiation technology be used for preservation of cultural heritage made of leather and in which conditions.