Mg-3Al-1Zn (AZ31) alloy samples with different starting textures have been processed using Equal Channel Angular Processing (ECAP) at 150C and 200C. The common temperature limit for ECAP of wrought AZ31 alloys has been reduced from 200C to 150C by suppressing tensile twinning activity. Twinning activity was reduced by either changing the starting texture or increasing the temperature. A crystal plasticity model was utilized to gain a better insight into the operating deformation mechanisms during ECAP. Suppression of tensile twinning and pronounced prismatic slip activity resulted in a crack-free, homogeneous deformation at 150C. In addition, twinning, when exists, was shown to have a significant effect on the promotion of DRX and shear band formation.