Micellar diffusion coefficient (DMDC), micellar hydrodynamic radius (RH) and average aggregation numbers (Nagg) of 1-alquil-3- methylimidazolium chloride (CxMeImCl x = 12, 14, 16) surfactants in aqueous solution have been determined by using voltammetric information obtained with disk microelectrodes. Ferrocene was used as redox-active electrochemical probe. DMDC values determined by extrapolation of the plot of diffusion coefficient versus surfactant concentration to the critical micelle concentration were found to be in good agreement with the literature values, based on static light scattering and theoretical calculations.