The article presents the results of research on reinforced walls with openings of various shapes made of calcium-silicate masonry units. The main aim of the conducted experiments was to determine the influence of the applied reinforcement, on the relationship shear stress – shear strain angle and the value of cracking and ultimate stresses. 12 walls with external dimensions of l = 4,45 m, h = 2,45 m, t = 180 mm with openings of different shape and dimensions were constructed and tested. In all reinforced models, the element reinforcement ratio was ρ = 0,07 (> ρmin = 0,05). The walls were tested at the initial compressive stress of σc = 0,1; 1,5 or 0,75 N/mm2. The significant influence of the reinforcement on the wall stiffness and the values of the analyzed stresses at cracking and ultimate was demonstrated.