In this study the effect of cerium addition on the microstructure of hypereutectic Al-15Si alloy was investigated. Experiments have been conducted on Al15Si alloys with Ce content in the alloy varied from 0 to 2.51 wt.%. The alloys were produced by casting in a permanent mould. Optical microscopy, X-Ray Diffraction (XRD) and Vickers microhardness were used in this investigation. The results showed that the addition of 0 to 2.5 wt.% of cerium led to the formation of precipitation of rod-like Al3Ce phase in the Al-matrix. The microhardness of the alloys increases with the increase in cerium content as a result of the Al3Ce precipitation.