Enhancing mechanical properties and suppressing vibration are important requisites in developing composite materials for dynamic structural applications such as automotive and aircraft. In this work, mechanical and vibrational properties of twill woven CFRP composites fabricated by compression molding, are studied by varying tow sizes (3k and 6k). Density, void, tensile, bending, impact strength, hardness, and free vibration tests were conducted as per ASTM standards to study their properties and investigate the impact of tow sizes on composites. In experimental modal analysis, Frequency Response Function (FRF) plots were also recorded. Scanning Electron Microscope (SEM) was used to analyse the fracture behavior of the composites. A comparison between the observed results of 3k and 6k twills are made and discussed in detail. From the experimental investigation, it is found that higher tow size decreases the tensile, flexural and hardness strength but increases the natural frequency and damping coefficient. Interfacial bonding between fiber and matrix was affected by the presence of voids in the composites as evident from SEM micrographs.