The structure of the AA5056-Al3Er composite and the initial alloy was studied by optical and scanning electron microscopy. The introduction of 0.23 wt.% particles does not modify the structure of the aluminum alloy, but, due to dispersion hardening, increases the ultimate tensile strength and ductility of the metal matrix. Rolling the AA5056-Al3Er alloy leads to a more uniform distribution of particles in the volume of the material, but does not increase its yield strength or ultimate tensile strength. A more uniform distribution of deformation due to the influence of Al3Er particles made it possible to increase the ductility of the AA5056 alloy.