A block wall system includes a plurality of T-shaped blocks having a head defining projecting load shoulders and a shaft having a first end attached to the head and a second end. There is also provided a plurality of complementary blocks having a first end and a second end. Each of the complementary blocks is shaped to fit securely between a pair of adjacent T-shaped blocks with the first end of each complementary block abutting the load shoulders of the T-shaped blocks to limit relative movement in a first axial direction. The preferred form to have the shaft of the T-shaped blocks wedge shaped and for the complementary blocks is to be wedge blocks. The wedge engagement between the wedge shaped shaft and the wedge blocks limits movement in a second axial direction.