Partially grouted reinforced masonry (PG-RM) shear walls are widely used in Chile to build low- and medium-rise buildings. This masonry typology can be constructed by using hollow concrete blocks or multiperforated clay bricks. In general, the unit type selection for a new construction depends on the material availability at the building location, although both unit types are equally used along the country. Even though the in-plane structural behavior of PG-RM walls constructed with concrete or clay units has been investigated through numerous experimental campaigns, none of them have directly compared the response of both masonry types. In this paper, experimental results of eight clay brick walls and ten concrete block walls tested under cyclic lateral loading are compared. From the comparative analysis, it is observed that brick walls have higher normalized shear strength than concrete walls, but lower deformation capacity. Despite these differences, both wall typologies exhibit a similar response when the effect on seismic design parameters of certain design variables, such as aspect ratio, horizontal reinforcement ratio, and axial pre-compression level, is analyzed.