Pt electrodes, modified by partial electrodeposited tin, were used as anodes for the catalytic electrooxidation of methanol in acid medium. Sn was electrodeposited galvanostatically and potentiostatically. Cyclic voltammetry was used to study the methanol electrooxidation. Pt modified with Sn proved superior to pure platinum as shown from the methanol peak current densities. Sn also improved the performance regarding the stability of the anode over repeated cycles. It was found that electrodeposited Sn facilitates the oxidation of intermediate poison products through a mixed homogeneous-heterogeneous catalytic mechanism.