In an attempt to improve the mechanical and thermal properties of natural rubber (NR) in order to expand its range of application, this work aims to prepare a high performance elastomer blend (MNR- PDMS) of it with hydroxyl terminated polydimethylsiloxane (PDMS-OH). The elastomer blend (MNR-PDMS) was prepared by first modifying the surface of NR with maleic anhydride and then blending it with PDMS-OH using a laboratory roll mill. A sulfur-based curing system was used to cure the blend. Different loadings of PDMS-OH (2, 3, 4 phr) were used to determine the optimum one. Fourier transform infrared spectroscopy (FTIR) was used to characterize the structure of MNR-PDMS elastomer blends. The cure characteristics, mechanical and thermal properties of the MNR-PDMS elastomer blends were studied in detail. Moreover, the surface morphologies of the prepared MNR-PDMS elastomer blends were studied using scanning electron microscopy (SEM). The results showed a remarkably improvement in the mechanical and thermal properties of the prepared MNR-PDMS elastomer blends compared to the unmodified vulcanized natural rubber, and 2 phr was the optimal loading to obtain elastomer with superior mechanical properties.