Wood-based panels are a group of products with a wide range of applications, which are not obtained from solid wood, but are made from its fragments, such as wood chips, sawdust or wood dust, which are usually waste from production. The recycled material, after being mixed with a binder, is compressed. As a consequence of such a process, different types of boards are obtained: MDF (Medium-Density Fiberboard), HDF (High-Density Fiberboard), fiberboard or particleboard. In response to the problems accompanying the use of MDF and HDF boards, a new type of CDF (Compact Density Fibreboard) wood-based boards has been developed. In the paper the strength properties of CDF panels reinforced with melamine films were investigated for four thicknesses: 6.4 mm, 8.4 mm, 10.4 mm and 12.4 mm. Young's modulus E, tensile strength Rm and percentage total extension at fracture At were determined from the static tensile test. The obtained results of the strength tests of wood-based panels were subjected to statistical analysis to determine the effect of the thickness of the panel on its strength. CDF boards are characterized by low total elongation at break of about 0.5% and show higher stiffness due to higher Young's modulus (at least 5,600 MPa). Statistical analysis has shown that for boards up to 12.4 mm thick, their thickness usually does not affect the strength properties. The only exception is the Young's modulus values for the thickness of 12.4 mm.