Sandcrete blocks have been in used in many nations of the world including Nigeria, playing a major role in the building industry. The material constituents, their mix, presence of admixtures and the manufacturing process are important factors that determine the properties of sandcrete blocks. This paper investigates the effects of a partial replacement of cement with rice husk ash (RHA) on some engineering properties of hollow sandcrete blocks with 1:6 cement-sand mix ratios. Single block size 225 x 225 x 450 mm, is produced with a vibrating machine. Results show that the addition of RHA produces blocks of lower density. Particularly, the density of the blocks decreases as the RHA content increases. The compressive strength of the block is also not enhanced. Results also reveal that the thermal and hygrothermal properties of the blocks are significantly affected. Key words: Sandcrete blocks, rice husk ash, compressive strength, hygrothermal properties, thermal properties.