The study investigated the possibility of using rape straw and expanded polystyrene for the production of low density particleboards. Particleboards with the core layer made of wood chips or rape straw, partly substituted with polystyrene (7%), were manufactured within the density range of 500 – 650 kg/ m3, and resinated with MUF resin. Our study confirmed that wood chip-expanded polystyrene (WP) and wood chip-rape straw-expanded polystyrene boards (WRP), of density reduced to 600 kg/m3, metthe mechanical requirements of the subject standard for boards intended for interior design (including furniture) and used in dry conditions. However, further density reduction required an increased resinationof the core layer.