The cavitation phenomenon accompanies the tensile deformation of most semicrystalline polymers when negative pressure inside the amorphous phase is generated. Over the years, this phenomenon has been marginalized, due to the common belief that it does not have any significant influence on the properties or micromechanisms activated during plastic deformation of such materials. In this article, for the first time, the influence of the cavitation phenomenon on the value of yield stress/strain, the intensity of the lamellae fragmentation process, the reorientation dynamics of the crystalline and amorphous component, the degree of crystals orientation at selected stages of deformation, and the amount of heat generated as a result of activating characteristic micromechanisms of plastic deformation were systematically analyzed. The research has been conducted for cavitating/non-cavitating polypropylene model systems with an identical structure of crystalline component during their tensile deformation. (C) 2016 Wiley Periodicals, Inc.