The electrochemical oxidation of adenosine has been studied in the pH range 2.3-10.0 using glassy carbon (GCE) and pyrolytic graphite electrodes (PGE). Voltammetric, coulometric, and spectral studies and product analysis indicate that the oxidation of adenosine occurs in an EC reaction involving a 6e(-), 6H(+) process at pH 3.0 to give alloxan, urea and ribose as the major products. On the other hand at pH 7.0 the oxidation of adenosine consumed close to 5e(-) per mole and an O-O linked dimer has been characterised as the major product. A tentative mechanism for the formation of the products has also been suggested.