The properties of hollow blocks of cements prepared using lime, calcined phosphogypsum waste from phosphoric acid fertiliser production, and power station fly ash, were measured to determine their suitability for construction applications. Hollow cubes with sides of 150 mm, and wall and web thicknesses of 20 mm, were prepared using a wide range of compositions. Following curing under water, the compressive strengths and water absorptions were determined according to Indian standard IS: 3952-1998. Durability was assessed by comparing the compressive strength of blocks cured in sodium sulphate solution with that of blocks cured in water. It was concluded that the blocks had sufficient strength for use in general building construction. 11 refs.