Industries such as aeronautics, automotive, aerospace, require low density materials with high mechanical and thermal resistance as an alternative, for which polymer matrix composites are usually chosen. In this work, the effect of the percentage variation of the MMT clay fraction in a polycarbonate (PC) matrix on its mechanical and thermomechanical properties is studied. To obtain this composite, powdered clay was used as reinforcement, in percentages of 1;1;5;2;3;3 and 5%, and Acrylonitrile Butadiene Styrene (ABS) as an additive in 7/3 w/w proportions. Tensile, Charpy impact, load deflection temperature (HDT) and Rockwell hardness (HRB) tests were performed. The composites with 3 and 5% clay exhibited a 49% increase in tensile strength, 33% in toughness, 17% in load deflection temperature and 44.16% in HRB hardness, with respect to the unreinforced matrix. This new composite material represents an innovative alternative that significantly outperforms the mechanical and thermo-mechanical properties of traditional polymeric materials.