Microstructure and microhardness of the copper wire obtained by the UPCAST method were studied. The microhardness distribution was investigated on longitudinal and transverse sections of wire rods with a diameter of 16 and 8 mm. It was revealed that the production of cast wire can be accompanied by plastic deformation of the surface layers. The surface layers of the cast wire rod have higher hardnesses than the central ones. The difference in microhardness of 17% was revealed for a cast wire rod with a diameter of 16 mm. The revealed hardening of the surface layers can cause a decrease in elongation.