In this investigation, we attempted to enhance the dyeability of polypropylene (PP) with disperse dyestuffs without adversely affecting its tensile properties. To this end, a special cubic experimental design was used to predict the effect of variations in the properties of a tricomponent mixture composed of PP, poly(ethylene terephthalate) (PET), and maleic anhydride grafted polypropylene (PP-g-MA) on the dyeability and tensile properties of the resultant polymer blend. The results illustrate that there seemed to be critical PET content, above which the blend's dye uptake tended to remain constant, but the tensile properties were adversely affected. Further analysis of the results indicated that the PP/PET/PP-g-MA blends in which the PET and PP-g-MA contents were in the range 10-15 and 4-5 wt %, respectively, gave maximal dye uptake and desirable tensile properties. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 3201-3210, 2011