Severe plastic deformation affects grain size and its distribution to a great extent and it in turn has an impact on the mechanical properties of the specimen. This paper mainly focuses on the microstructure and mechanical properties of the Al 5083 processed by equal channel angular pressing at room temperature. The grain size, crystallite size and dislocation density were evaluated by transmission electron microscopy and X-ray diffraction peak profile analysis. The crystallite size and dislocation density were calculated by Williamson–Hall plot method. The mechanical properties such as hardness, tensile strength increase as the number of passes increases. Interestingly percentage of elongation also increases as the number of passes increases. The factors responsible for the change in mechanical properties were identified by electron diffraction and discussed.