The effect of ionizing radiation on the parameters of hydroconversion of vacuum tower bottoms (VTB) has been studied, and optimal conditions for the hydroconversion of irradiated VTB have been found. The structural characteristics of the reaction products and the process chemistry have been investigated using a set of instrumental techniques. It has been shown that the use of electron beam-irradiated feedstock increases considerably the effectiveness of hydroconversion in the presence of catalyst nanoparticles.