A computer simulation of the voltammetric behaviour corresponding to the electroreduction of the anodically formed thin PbO layer on Pb electrodes in sulphuric acid solutions is presented. The model implies pathways leading to the electroreduction of the thin PbO passive layer which grows underneath the PbSO4 crystals, according to the main contribution of a progressive 3D nucleation and growth mechanism under charge transfer control, including a death correction term to take into account the disappearance of right circular cone phase centres by overlapping. The corresponding rate determining step can be expressed by gradual growing of the surface fraction of Pb substrate not covered by PbO species which are located between the metal and the outer porous PbSO4 membrane. Calculations are based on potential-dependent kinetic data derived from potentiostatic current transients using non-linear fit routines. Good agreement was found between theory and experimental results.