The mechanical properties and diffusion behavior of marble waste (MW)-filled acrylonitrile-butadiene rubber (NBR)/high density polyethylene (HDPE) blends were studied as a function of blend composition. A sulfur curing system was employed to crosslink the thermoplastic elastomer (TPE) blends. The results obtained showed that the physical properties of vulcanized NBR/HDPE blends were enhanced with the addition of HDPE in MW-filled vulcanized NBR/HDPE blends. Mechanical properties such as stress-strain behavior, tensile strength, modulus, and % elongation at break and tear strength, were assessed and found to fluctuate with the blend ratio. HDPE-incorporated vulcanized NBR/HDPE blends have been found to reveal a reduced toluene uptake trend compare to the NBR compound.