Cement-based materials are the world's most widely utilized construction materials due to their high compressive strength. However, they need reinforcement to withstand direct or indirect
tensile forces. This study evaluated the potential use of 3D-printed polymers as an alternative reinforcement in cement-based composites. Polyethylene terephthalate glycol (PETG), Polyamide (PA), and Acrylonitrile butadiene styrene (ABS) based triangular and honeycomb-patterned 3D-printed reinforcements were incorporated into cement-based composites, and their mechanical performances were compared under three-point flexural tests by considering both polymer and pattern type. Both triangular and honeycomb patterns enhanced flexural behavior. Considering all filaments, the honeycomb pattern was found more effective than the triangular one for increasing flexural strength, deflection capacity, and toughness up to 46.80%, 251.85%, and 77.66%, respectively. In the case of filament type, 3D-printed PA-type filament in a honeycomb pattern preserved flexural strength, enhanced deflection capacity, and increased flexural toughness with pseudo-deflection hardening behavior. 3D-printed honeycomb patterned reinforcements produced by PA have the opportunity to be used in the manufacture of cement-based composites.