The aim of this research is to evaluate the physical, chemical, thermal, and mechanical properties of Itauba (Mezilaurus itauba) wood fiber and Itauba wooden board. The chemical composition presented 33, 29, and 10% lignin, cellulose, and hemicellulose, respectively. The thermal stability was found to be 250 °C for both atmospheres (air and nitrogen), and the simulated TG curve was similar to the one performed on a nitrogen atmosphere. Cone calorimetric results showed a higher steady state when compared to other wood fibers found in the literature with peak heat release rates of 281.762, 424.029, and 482.335 kW/m²when exposed to constant levels of radiant heat flux of 25, 50, and 75 kW/m²at similar weights and densities. Furthermore, X-ray diffraction (13.5% crystallinity) and mechanical tests (flexural and tensile Young’s modulus of 12010 and 969.9 MPa, respectively) were performed on the Itauba wooden board. The tensile results showed to be higher than propylene composites reinforced with 40% wood fiber found in the literature while the storage modulus obtained in the dynamic mechanical thermal analysis found to be higher (11.5 GPa at −130 °C) than most of the commercial thermoplastics used in the industry (polypropylene (9 × 10²MPa), high-density polyethylene (2 × 10³MPa), and polyvinyl chloride (3000 MPa)). This study showed the potential in using Itauba wooden boards in replacing many commercial products, mainly when an adequate mechanical performance is required.