Microstructure evolution and corrosion behaviour of ultrafine-grained copper processed by equal channel angular pressing (route Bc) were studied. The results of TEM investigation of the microstructure evolution are presented along with the measurements of the corrosion potential, the corrosion current density and the anodic current density for two aggressive media, viz. 3% NaCl and 1M H2SO4. An important finding and a good news is that the corrosion behaviour of ECAP copper is not inferior to and does not qualitatively differ from that of the coarse grained material. Moreover, it was shown by SEM investigation that the corrosion damage is more homogeneous in ultrafine grained ECAP processed copper than in its coarse grained counterpart.