A model that accounts for the screened electrostatic interaggregate interactions in polydisperse micellar solutions is presented. The case of moderately concentrated systems in the presence of added salt is analyzed. The treatment presumes the use of the linear theory of micellar growth and the hypothesis for the uniform distribution of each type of aggregate throughout the whole volume of the solution. The results show that systems with lower electrolyte concentrations and with lower polydispersity are more sensitive to intermicellar interactions of this kind, especially at lower temperatures. Systems with higher polydispersity are less sensitive, although the interactions there also tend to shift the equilibrium distribution curve toward increased mole fractions of the shorter aggregates, thus reducing the overall polydispersity of the solutions.