Use of lignocellulosic materials in particleboard has turned into an alternative for the reuse of such materials, which are abundant and may have precarious disposal techniques. The present study fabricated particleboards using industrial sawmill waste from tropical hardwoods (a mix of species) and sugarcane bagasse with castor oil-based bicomponent polyurethane resin and evaluated the influence of the incorporation of sugarcane bagasse (0, 10, 20, 30, 40, and 50%) on the physical and mechanical properties of the composites. The particleboards were produced according to the Brazilian Standard ABNT NBR 14810 (2018), and performance requirements were assessed using Brazilian and international standards. Some of the particleboards met standardized requirements, with Treatment 5 (50% sawdust and 50% bagasse) showing better performance, indicating the possibility for use indoors in dry conditions. The addition of sugarcane bagasse increased dimensional stability of particleboards when compared with panels manufactured with timber residue. Statistical analysis indicated the percentage of bagasse was significant, increasing physical and mechanical properties when compared with the reference treatment.