Accurate description of the mechanical response of AZ31 Mg requires consideration of its strong anisotropy both at the single crystal and polycrystal levels, and its evolution with accumulated plastic deformation. In this paper, a self-consistent mean field crystal plasticity model, viscoplastic self-consistent (VPSC), is used for modeling the room-temperature deformation of AZ31 Mg. A step-by-step procedure to calibrate the material parameters based on simple tensile and compressive mechanical test data is outlined. It is shown that the model predicts with great accuracy both the macroscopic stress–strain response and the evolving texture for these strain paths used for calibration. The stress–strain response and texture evolution for loading paths that were not used for calibration, including off-axis uniaxial loadings and simple shear, are also well described. In particular, VPSC model predicts that for uniaxial tension along the through-thickness direction, the stress–strain curve should have a sigmoidal shape.