Treatment of chrome grain and also heavily retanned leather with three grades of chitosan enhanced the depth of shade of a typical acid and a direct dye on the substrates. For each type of leather, the dyed treated leather was found to be of a similar, but deeper hue and possessed superior fullness and handle to its dyed, untreated counterpart. The extent of shade intensification furnished by pretreatment was greater for the acid dye than the direct dye, possibly due to the greater substantivity of the direct dye for the cationic polymer within the pretreated leathers. Despite their greater colour strength, the wash fastness of the pretreated dyeings was comparable to that of their dyed, untreated counterparts.