This study aimed to enhance the properties of aluminiumsilicon (Al-Si) alloys by adding zinc oxide as a reinforcing material. This study was a type of pre-experimental design called the one-shot case study, in which sample groups subjects were given treatments and then observed. The steps included melting the aluminium-silicon in a furnace at 900° C, adding a certain amount of zinc oxide (0.05%, 0.1%, or 0.2%), stirring the mixture for 1 minute, and pouring it into a permanent mould. Results showed that, among the three specimens, the specimen reinforced with 0.2% zinc oxide had the highest tensile strength of 23.9 kg/mm 2 , the greatest hardness of 134.4 HV, and a flat surface with evenly distributed grains and more brittle fracture.