The use of rice husk ash as aggregate for foundry sand mould production has been studied. 5-25 weight percent rice husk ash was added to the sand mixture. The chemical, physical and mechanical properties measured include: chemical analysis of the rice husk ash, particle size, density, permeability, compactibility, mouldability, moisture content, green compression and shear strength, and dry compression and shear strength. The results revealed that addition of rice husk ash to Rayfield Silica sand increased the mouldability, compactibility, grain fineness number, and both green and dry strength, but slightly decreased the density, permeability and moisture content. These results show that better properties are achievable by addition of rice husk ash to Rayfield silica sand. The improved properties lead to enhancement of the moulding characteristics of the foundry sand.