Poisoning of different precious metals on carbon catalysts (Pd/C, Ru/C and Rh/C) was observed in the hydrogenation of some pyrrole derivatives, under mild reaction conditions, in non-acidic medium. In all reductions, the catalysts were poisoned by the hydrogenated products (pyrrolidines) more strongly than by the reactants pyrroles). A comparison concerning poison sensitivity of the catalytic metals was also made.