Mediatorless (direct) electron transfer between Myrothecium verrucaria bilirubin oxidase and spectroscopic graphite electrode has been demonstrated. The electrochemical activity of the enzyme under aerobic and anaerobic conditions is clearly shown using cyclic voltammetry. It is concluded that the T1 site of the enzyme is the first electron acceptor, both in solution (homogenous case) and when the bilirubin oxidase is adsorbed on the surface of the graphite electrode (heterogeneous case).