The electrocatalytic oxidation of hydrazine has been studied on a glassy carbon electrode modified by electrodeposition of chlorogenic acid (CCA), using cyclic voltammetry, chronoamperometry and rotating disk voltammetry as diagnostic techniques. At this modified electrode, the oxidation of hydrazine to nitrogen occurs at a potential where oxidation is not observed at the bare glassy carbon electrode. It has been found that the catalytic current depends on the concentration of hydrazine and solution pH. The overall number of electrons involved in the catalytic oxidation of hydrazine and the number of electrons involved in the rate determining step were found to be 4 and 1, respectively. It has been shown that the catalytic oxidation of hydrazine obeys first-order kinetics with respect to hydrazine concentration. The diffusion coefficient of hydrazine was also estimated using chronoamperometry. Finally, the catalytic rate constant of hydrazine oxidation at a CGA modified electrode was determined by cyclic voltammetry and rotating disk electrode experiments.