Grafting of electroactive p-phenyldiazonium derivatives was performed on carbon electrodes. Reduction potentials were determined for commercial and new synthesized diazonium salts, in relation to the electronic behaviour of the para substituents of the diazophenyl groups. Their covalent attachment on the electrode surface was characterized through electrochemical experiments. The effect of varying several parameters (concentration, substituent, duration...) was investigated for potentiodynamic and potentiostatic grafting reactions. Spontaneous binding was identified by simply deeping the electrodes in diazonium salt solutions, affording low coverage (lower than 3%) and grafting densities of less than Gamma = 3.9 . 10(-11) mol . cm(-2).