Masonry is one of the eldest construction systems in the building industry, currently in use because some advantages like compressive capacity, traditional aesthetics, low cost and good practices. However, damages recorded in walls as a result of cyclic loads, have given rise to an important development in the area of strengthening and rehabilitation of this type of structural element. To counteract this problem, the vegetal FRCM arises as a strengthening competitive system for the improvement of the mechanical properties of masonry walls. In this study, an analytical model evaluates the behaviour of walls strengthened with FRCM. The model is compared with existing codes and it is validated with experimental results of shear diagonal-compression tests and shear under cyclic loads. It proved to be an effective calculation tool, useful enough to reproduce the behaviour of masonry walls strengthened with FRCM, but limited to failures not related with debonding neither sliding of FCRM material and substrate.