Square wave voltammetry (SWV) in the case of irreversible reactions has been studied systematically by digital simulation. A simple expression for the peak current and a method for the evaluation of the charge transfer coefficient are given. The height of the voltammograms increases greatly when pulses of large amplitude are used. In this case, it has been shown that the observed response essentially reflects the underlying potential staircase contribution. This indicates that, in the domain of low concentrations, the response in staircase voltammetry can present a better signal to noise ratio than that in SWV.