The charge transfer (ct) band of N-alkyl pyridinium iodides has been studied in a binary solvent system (polar + nonpolar). The observed band shift has been explained in terms of a chemical model involving a stepwise solvation by the polar component. The band position has been found to be a linear function of the mole fraction of the polar component indicating that the solvent composition in the immediate neighbourhood of the solute is the same as that in the bulk. Specific solvation effects appear to play a role in some mixed solvents, where the percentage of the nonpolar part is high. An idea of the energy change in the stepwise solvation process can be obtained from nonspecific solvation effects.