Mg-3Al-1Zn (AZ31) alloy was caliber rolled isothermally in the temperature range of 250-450 °C to develop fine grains of 3.6-12.5 μm. The stress-strain curves obtained from tensile tests at room temperature were found to vary with the temperature employed in caliber rolling. Maximum tensile strength of 290 MPa and ductility of 13.5% were obtained upon caliber rolling at 300 °C as compared to 188 MPa and 15.2%, respectively, in the mill-rolled condition. The variations in tensile properties are explained by the concomitant grain size, texture and twins obtained as a function of caliber rolling temperature. © 2013 National Engineering Research Center for Magnesium Alloys of China, Chongqing University.