The influence on electrode polarization from fast nucleation reactions in the solution phase within an electrode surface were analysed for dissolving-precipitation reactions. For electrode reactions where sparingly soluble reaction products are formed it is predicted that a polarization maximum can occur in galvanostatic transients. The maximum effect is explained from a fast build up of dissolved species which are in a reversible exchange with the electrode and then followed by a nucleation reaction in the oversaturated solution which consumes the reversible species which give a decreasing concentration polarization. NOTATION double layer capacitance, #/cm' concentration of species j, mole/cm3 saturation concentration of monomeric species, I-l-d+d diffusion coefficient for species j, cm'/S the Faraday equivalent, 96487 As per mole equivaicnt current density, A/cm' exchange cd, A/cm2 constant load cd, A/cm2 species index kinetical constants. cm3/~mol. s\ equilibrium constants ikfine'd 'by equation (13), dimensionless species index in equation (15) the number of monomeric units m the largest polymeric unit Avogaros number, 6.023 x 1O23 molecules/g mole average radius of species j, cm universal gas constant, 8.3143 JK-' mole-' time, s temperature in Kelvin degrees, K number of electrons transferred per reacted monomeric mole units coordinate outside the electrode, cm anodic charge transfer coefficients (0.5 F/RT) V-' cathodic charge transfer coefficients (0.5 F/RT) v-1 kinetical constant defined by equation (15) and (24), mole/cm', s overpotential, V charge transfer overpotential, V concentration overpotential, V