This study aimed to determine the influence of mould materials on microstructure, mechanical properties and sliding wear behaviour of A356 alloy. Three separate moulds were made using ferrochrome slag, blast furnace slag and sand silica. The castings were produced separately on three moulds. All these samples were solutionized at 540OC for 8 h and aged at peak ageing condition (T6) 170OC 7 hrs. These were characterized for its microstructure, SDAS, hardness, and dry-sliding wear behaviour studies. Dry sliding experiments have been performed with a pin on a spinning disc. A pin size of 10 mm × length of 30 mm is selected. Metallographic results reveal casting made in Fe-Cr slag mould shown fine grain microstructure followed by GBF slag and sand mould. SDAS values of three mould castings were observed are Fe-Cr slag is 17, GBF slag is 31 and sand mould is 42. Improved hardness values were obtained for castings made in Fe-Cr slag moulds (122 VHN) followed by silica sand (114 VHN) and finally GBF slag (111 VHN). Thorough wear analysis was carried out on all these castings; results show samples of Fe-Cr slag moulds showed better wear resistance than either GBF slag or sand mould samples.