The structural state of the 5083 Al-Mg alloy after homogenizing annealing by different regimes have been investigated using the electron-microscopy method. Intermetallic compounds of solidification origin have been identified, and particular features of transformation of their shape and composition depending on the annealing regime have been established. A relationship between the structure of the homogenized alloy and the character of its grain structure, which is formed in the course of dynamic recrystallization upon subsequent hot working, has been found. Structural parameters that are responsible for the improved mechanical properties of the alloy subjected to deformation have been determined.