To obtain a cast of better quality through vertical centrifugal casting, it is essential to optimize the process parameters like rotational speed, volume fraction, aspect ratio etc. In the present investigation casts of eutectic Al-5%Si alloys with zirconia(ZrO2) reinforcement were obtained with mould wall thickness 4mm, 6mm and 8mm at rotational speed of 300 rpm, 400 rpm and 500 rpm. Hardness and tensile strength were measured However, hardness of casts with higher wall thickness was found greater.When Al-5% Si is reinforced with Zirconia at 500 rpm highest tensile strength has been observed whereas the cast obtained at 300 rpm has the lowest tensile strength.