The interest in electrical conducting materials is presently increasing rapidly, especially in the automotive industry. Aluminium is suggested to be an attractive alternative to copper. In the present work, the electrical conductivity as well as the mechanical properties are measured for a series of Al-0.6Mg-0.5Si samples subjected to solution treatment, cold rolling and aging treatment. The microstructures (including grain and cell size, precipitate size and density, and dislocation density) are characterized by optical, scanning and transmission electron microscopy. It is shown that both the plastic strain and the aging treatment strongly affect the electrical conductivity as well as the mechanical properties, and the microstructures are used as a basis for interpreting the results.