The use of clay hollow blocks is common for new constructions in many parts of Europe. The results of 8 full-scale shear tests of block-masonry panels (dimensions 1.60x0.90x0.25 m) are reported in this paper. Non-defective and defective wall panels were tested in shear in the laboratory. Typical failure modes are investigated, not previously reported in the scientific literature. Test results show that the lateral load capacity of the panels is highly affected by construction defects. Furthermore, CFRPs were used in this research as local reinforcement (repair) in the area around the cracks previously opened in the masonry material. The lateral capacity for CFRP-repaired panels was restored to the original value of non-defective panels, indicating that the CFRP-repair of cracked panels is viable solution. An explanation for this phenomenon is suggested, which indicates that the high tensile strength of CFRPs can be effective in repairing cracked block-masonry. It is also argued that this large stress level of the CFRPs leads to a premature tensile CFRP crisis or a splitting failure of the blocks’ shells.