In this Study, three-layer particleboards were produced from mixtures of sunflower stalks (Helianthus annuus L.) and Calabrian pine (Pinus brittia Ten.) particles at various ratios. Urea-formaldehyde adhesive was used as a binder in three-layered particleboards with a density of 0.70 g/cm(3). The sunflower stalks and Calabrian pine wood particles were mixed at the ratios of 25:75, 50:50, and 75:25. Also, 100 percent sunflower stalks and 100 percent calabrian pine boards were manufactured for control. All boards were tested for physical properties (thickness swelling and water absorption) and mechanical properties (internal bond strength, modulus of elasticity, modulus of rupture, and screw-holding strength). It was observed that the properties of the panels were the best with the 50:50 mixture of calabrian pine and sunflower stalk particles in the boards. The properties of all the panels manufactured met the minimum requirements for general grade particleboards. This study showed that the renewable sunflower stalks and calabrian pine particles can be used at different ratios in the production of particleboards and the resulting panels call be utilized for general purposes as well as furniture for interior environments.