The influence of microstructure evolution on microhardness and electrical resistivity of ultrafine grained (UFG) commercial purity Al under annealing at different temperatures within a range of 363–673 K was studied. The initially coarse grained Al was processed by high pressure torsion (HPT) technique for the formation of UFG structure. The microstructure was characterized by electron backscattering diffraction and X-Ray diffraction. It was shown that annealing of UFG Al at temperatures within a range of 363–473 K leads to simultaneous increase of microhardness (by 6–13%) and electrical conductivity (by 4–8% at 300 K). The correlation between microstructural features and the resulting properties were analyzed. The average width s of potential barriers at grain boundaries (GBs) in HPT-processed Al was estimated in the frame of a tunnel model. The obtained large value of s compared with the GB crystallographic width is associated with elastically distorted lattice near GBs. The obtained results suggest a new way to increase simultaneously strength and electrical conductivity of UFG Al alloys by an appropriate annealing.