Magnesium alloy Mg-1.0%Zn-0.3%Ca was processed by equal channel angular pressing (ECAP) with the aim to refine its microstructure. ECAP was found to reduce the average grain size from 106.0 ± 2.05 μm in the initial state to 4.0 ± 0.19 μm and 8.0 ± 0.18 μm in the transverse and longitudinal sections, respectively. This resulted in a slight strengthening (the yield strength and the ultimate tensile strength rose from 92 and 194 MPa in the initial stat to 106 and 215 MPa after processing, respectively). The main advantage of ECAP is the concurrent increase of tensile elongation from 12.8% to 23.9%. The absence of pronounced strengthening and a significant increase in ductility are associated with the formation of an inclined basal texture, along with activation of prismatic slip during ECAP. It was also shown that ECAP leads to an increase in the fatigue limit of the alloy from 100 MPa to 110 MPa and does not impair its resistance to chemical corrosion.