Cobalt is currently used in the production of diamond reinforced metal matrix composites (i.e. stone-cutting tools). Herein, how sintering temperature and matrix composition influences the material properties of diamond reinforced MMCs was explored. The aim of this work is to produce diamond reinforced metal matrix composites based on Fe-Co compositions with and without B4C are processed by a PM method using a hot pressing technique. The effects of Fe and B4C additions on the characteristic of diamond impregnated Co matrix composites have been investigated. Samples reinforced with and without B4C having two different compositions (different Fe/Co ratio) were produced under 25 MPa pressure and sintered at 1000 degrees C temperature. After sintering, hardness tests were carried out and wear tests were performed by pin-on-disc. The results showed that addition of Fe caused slightly decrease in the hardness of the matrix. However, reinforcing with B4C increased the hardness of the matrix. It is observed that wear resistance of B4C reinforced Fe-Co metal matrix composite was greater than that of composites without reinforcement. SEM and EDX techniques were used to characterize the composites.