In the present paper the experimental results of in-plane shear tests on masonry walls subject to cyclic loads under constant axial load and externally strengthened with composite grid embedded in a cementitious matrix are synthetized. The experimental results have been then compared with the numerical outcomes given by a bi-dimensional Finite Element Model. The FE model has been also used for carrying out several parametric analyses aimed at evidencing the effectiveness of the reinforcement on both strength and displacement capacity of the wall by varying the shape factor of panel, the compressive strength of the mortar layer and the axial stiffness of the composite grid. Finally, the effectiveness of the strengthening with mortar layers reinforced with a traditional steel grid has been investigated and compared with the innovative strengthening intervention.