The integration of nanoalumina reinforcement into polymer and cement composites represents a promising avenue for advancing material performance and functionality across diverse industries. By leveraging the exceptional properties of nanoalumina, including mechanical strength, thermal stability, and chemical inertness, researchers and engineers can develop innovative composites with tailored properties for specific applications. As research continues to progress and technology matures, nanoalumina-modified polymer and cement composites are poised to play a pivotal role in shaping the future of materials science and engineering, driving innovation, and pushing the boundaries of material performance and functionality. The book provides an overview of the latest advances in the production and properties of polymer and cement-based materials modified with AL2O3 nanoparticles in terms of the interaction of the nanoalumina with the polymer or cement matrix.