This experimental study compares two scaled unreinforced masonry (URM) walls before and after being repaired by grout-injected ferrocement overlay reinforcement (GFOR), with the aim of investigating the effectiveness of an alternative ferrocement overlay technique. In the experiment, loading was performed on a multistory opening URM wall to induce damages, and the reinforced wall (defined as FRM) was retested using the same procedure. A comparative analysis of the seismic performances of the two walls in terms of failure modes, bearing capacity, hysteresis curve, energy dissipation capacity, and deformation behaviors was performed. The experimental results indicated the following. (i) The application of GFOR on the damaged URM wall altered its diagonal shear failure into the flexural-dominant mode. (ii) The ultimate resistance and residual strength of FRM increased by 6% and 13%, respectively, compared with those of URM. (iii) The ultimate and residual deformations of FRM increased by 110% and 60%, respectively, compared with those of the URM. (iv) The ductility of the overall walls improved from 2.48 to 2.72. This study verified the reasonability and effectiveness of the application of GFOR to damaged masonry structures. (C) 2021 Elsevier Ltd. All rights reserved.