Abstract: This work investigated on the strength poperties of sandcrete hollow blocks produced with sludge as partial replacement for river sand. The properties considered were the compressive strength and water absorption. A total of 16 sandcrete blocks were produced with a single mix ratio of 1:6 (cement:sand) using a standard mould of 450mm x 225mm x 225mm having two hollow size of 131mm x 154.5mm x 225mm.