Blends of a polyester hot melt resin and a poly-α-olefin hot melt resin were modified using the reactive compounding technique. The effects of the compatibilizers were evaluated by studying the mechanical properties, the morphology, and the thermal properties of the modified blends. A pronounced compatibilizing effect was obtained with dual compatibilizers composed of maleated polypropylene and poly[methylene (phenylene isocyanate)] (PMPI). The addition of 1 phr of PMPI was sufficient to improve the elongation and tensile strength. From the results, it is anticipated that PMPI can be used as an efficient coupler to enhance the compatibility of immiscible polyester/polyolefin blends. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40232.