The current investigation involves the fabrication and characterization of an aluminium metal matrix composite reinforced with sintered metal preforms. Two types of metallic preforms were used (steel and stainless steel) and a variety of squeeze casting conditions were investigated using systematic design-of-experiments techniques to determine the effect of casting conditions on the composite microstructure and mechanical properties. It was observed that a detrimental reaction phase containing iron, aluminium and silicon formed around the metallic preform particles, with a lower volume fraction of reaction phase forming at the lower melt casting temperature. This reaction phase appears to promote premature fracture by facilitating crack initiation and propagation. The stainless steel-reinforced composites had a smaller volume fraction of reaction phase and exhibited superior properties compared to the steel-reinforced composites.