Abstract: The physico-mechanical properties and the Infra-red (IR) spectra (obtained by applying the Attenuated Total Reflectance (ATR) technique) of high density polyethylene (HDPE)/ethylene propylene diene terpolymer (EPDM) blends were investigated using a Zwick Tensile Testing machine and a Fourier Transform Infra-red (FTIR) spectrometer. Three kinds of cure systems were used: sulfur, tetramethylthiuram disulfide (TH) and 2-mercaptobenzothiazole (M); sulfur, tetramethylthiuram disulfide (TH) and zinc-diethyldithiocarbamate (ZDEC); sulfur, tetramethylthiuram disulfide (TH) and diphenylguanidine (D). The composition of HDPE and EPDM was fixed at 50/50 by weight and the ratio cure accelerators/sulfur was varied from 0.4 to 6.34 by weight. Results indicated that polymer alloys EPDM/HDPE containing as cure agents Sulfur, TH and M, in a ratio cure accelerators/sulfur = 6.34 and 1.85, respectively, showed improved physico-mechanical properties as compared to the other polymer blends. This behavior was confirmed by the recorded ATR-FTIR spectra of the studied samples.