Abstract: The masonry block wall system comprises masonry blocks fastened together with interconnecting threaded steel fasteners. Four fasteners on each block connect with a pair of identical blocks immediately above and a pair of identical blocks immediately below the block. The resulting masonry wall is structurally sound and allows large vertical chases or conduits for electrical, plumbing and the like. Unlike conventional masonry, the construction of the present masonry wall does not require specialized knowledge and skill of a mason and is relatively easy to build. As well, the masonry wall system is not dependent upon weather during construction and can be de-constructed without demolition.