In this work, a blend of polypropylene (PP) and two types of thermoplastic polyolefin elastomers (TPO) with varying content were prepared by melt mixing. The TPOs were either ethylene- or propylene-based copolymer. The mechanical response and morphology of the blends were investigated using tensile and impact tests and scanning electron microscopy (SEM) technique. There was significant increase in the notch impact strength of the TPO-modified PP, which was an outcome of fine dispersion of TPO inclusions. However, the transitions from brittle to tough behavior in tensile and impact mode tests were not coincident in the case of ethylene-based TPO. Keywords: blends, morphology, mechanical properties.