The aim of this study was to examine the possibility of enhancing the mechanical properties of laminated oak elements using glass and carbon fiber meshes in combination with polyurethane adhesive, instead of the commonly used epoxy resin, which is complex for industrial application. The research was conducted on laminated oak beams with dimensions of 60 x 70 x 1000 mm, reinforced with pre-stressed fibers and bonded with polyurethane adhesive. Their mechanical properties were tested using the four-point bending method while tracking deformations with the ARAMIS optical 3D system. The results showed significant improvements in the mechanical properties of the reinforced samples compared to the non-reinforced ones, with an increase in the ultimate breaking force by 29-41% and a reduction in displacement at maximum load by 4-15%. The effective stiffness of the samples increased by 37-56%, depending on the type and amount of reinforcement. The reinforcement with a single layer of carbon fiber proved optimal due to the best ratio of property improvement to material consumption. The study also demonstrated that polyurethane adhesive can be an effective substitute for epoxy resin, providing satisfactory strength and adhesion without the need for complex procedures and high costs. These results suggest that laminated wood elements reinforced with carbon and glass fibers, using polyurethane adhesive, could be used in various structural applications where high mechanical properties and aesthetic quality are required.