Concrete block masonry walls play a significant role in building construction. Due to their brittle nature and poor tensile strains, masonry structures are vulnerable to failure under axial and lateral loads. Auxetic materials exhibit negative Poisson’s ratio (NPR) effect and thereby demonstrate large deformation capacity, shear modulus and superior energy absorption properties. This study investigates the use of these materials as embedded medium into concrete block masonry to enhance its structural performance under compression loading conditions. Re-entrant chiral auxetic (RCA) structures which have chiral and re-entrant geometries combined for enhanced mechanical properties were employed in this research for embedding into bed mortar layers and for reinforcing the grout. The RCA meshes were fabricated by 3D printing using Polylactic Acid filament. The printed structures were characterised for their uniaxial tensile behaviour. The tested RCA structures were then embedded into wet mortar joints for hollow concrete block prisms and in grout filled in the block cores for developing fully grouted prisms. The RCA embedded concrete block prisms were tested under direct compression to determine their strength and deformation attributes. The results revealed improvement in the performance of auxetic embedded concrete block prisms in terms of ductility and energy absorption when compared to traditional concrete block prisms. In addition to that, flat plastic post-peak portion was observed from the stress-strain curves under compression.