The influence of C content on the electrochemical corrosion behavior of nanostructured WC-Co hardmetals was investigated. WC powder with an average grain size dBET 95 nm and with an addition of VC and Cr3C2 as a grain growth inhibitors was used as starting powders. The mixtures with 5 wt. % and 10 wt. %Co and 15 wt. %Co were consolidated by sinter-HIP process. The samples were researched by direct current and alternative current techniques in the solution of 3,5 % NaCl at room temperature. Corrosion parameters like corrosion potential (Ecorr), corrosion current density (jcorr) and polarization resistance (Rp) were determined by electrochemical techniques. On the basis of conducted research conclusions about C content on electrochemical corrosion resistance are brought.