This work presents an analysis of the microstructural, mechanical and corrosion properties of two binary Mg-Zn alloys. Mg-6 wt%Zn and Mg-12 wt%Zn cast alloys were subjected to annealing followed by quenching and processed via equal channel angular pressing with applied back-pressure (ECAP-BP). After ECAP-BP, both alloys were thoroughly examined and showed partially recrystallized and highly deformed areas. High-angle annular dark-field imaging revealed a difference in Zn content across the α-Mg matrix of the Mg-12 wt%Zn after ECAP-BP due to the growth of MgZn 2 nanoparticles. Electron energy-loss spectroscopy (EELS) was carried out to qualify an average Zn content in these areas, and a variation in Zn content up to 2 at.% was found. Compression tests revealed mechanical anisotropy and a significant increase in the strength of both alloys after ECAP-BP. The yield strength, σ 02 , was in the range from 269 to 385 MPa depending on the composition and compression axis. The initial state alloys showed yield strengths, σ 02 , of only 75–150 MPa but improved ductility. The corrosion rates of the Mg-Zn alloys in the initial state, evaluated using a hydrogen evolution method in NaCl solution, were higher for Mg-12 wt%Zn. The corrosion rates of both alloys after ECAP-BP were higher than those of the initial state. Light microscopy observations did not reveal any preference for corrosion propagation, including transcrystalline, intercrystalline or interphase corrosion, in any of the materials. [ABSTRACT FROM AUTHOR]