In this work, Al-4wt.%Cu composites comprising two differently sized ZrC reinforcing particles (157 mu m and 8 mu m) were fabricated by high energy ball milling and vacuum hot pressing. Vacuum hot pressing experiments were carried out at 550 degrees C under a pressure of 70 MPa on Al-4wt. %Cu composite powders ball milled for 3h. Effects of reinforcement size on the microstructural and physical properties of the composites were investigated by X ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) techniques. Following vacuum hot pressing, approximately relative density values of 98 % were achieved for all hot pressed Al-4wt.%Cu composites. Highest microhardness values were measured for the hot pressed Al-4wt.%Cu composites containing the smallest sized ZrC reinforcing particles (8 mu m). On the basis of analysis, in addition to the Al, ZrC and Al2Cu phase reflections, a tetragonal Al7Cu2Fe phase was formed due to iron contamination from balls and/or vial in the metal matrix composite during MA process.