The electro-oxidation of atenolol has been studied at a glassy carbon electrode in tetramethyl ammonium chloride in methanol media by using cyclic voltammetric technique. Effects of anodic peak potential (E-pa), anodic peak current (i(pa)) and heterogeneous rate constant (k(o)) have been discussed. Single irreversible voltammogram was observed. The effects of scan rate, concentration, dielectric constant and temperature were evaluated. The electro-oxidation product of atenolol has been identified as 2-[4-(3-isopropylamino-2-oxo-propoxy)-phenyl]-acetamide involving 2-electron oxidation. The electrode processes were shown to be diffusion controlled and irreversible involving adsorption effects.