A carboxypeptidase B (CPB) has been purified from dogfish (Scyliorhinus canicula) pancreas and partially characterized. The purification procedure included acetone precipitation, ion-exchange chromatography on a CM-cellulose column and gel filtration on Sephadex G-75. The purified enzyme migrates as a single band both on PAGE and SDS-PAGE. Its molecular mass is estimated to be about 32 kDa. The optimum of activity is obtained at pH 7.5–8.2. The enzyme is inhibited by typical metal-chelating agents (EDTA and o-phenanthroline) and by Hg2+. It is activated by Co2+, l-cysteine and by heat treatment at 40° and 50°C. Kinetic parameters, Km and kcat, of native enzyme, Co2+-activated CPB and heat-treated CPB have been determined