In this paper, the impacts of heartwood and sapwood usage on the physical, mechanical, and surface properties and formaldehyde emission of particleboard are investigated. European Larch (Larix decidua) trees are chosen as a raw material. The logs are divided into three segments: sapwood, heartwood and total wood. The highest amounts of cellulose (51,54%), and hemicelluloses (22,24%) in the sapwood, followed by total wood, and the heartwood, respectively. However, the highest amount of lignin (30,54%) was found in the heartwood. The highest extractives values are obtained from heartwood, followed by total wood, and the sapwood, respectively. While the lowest pH value (3,03) is found in heartwood, the sapwood samples provide the highest values (4,95). The highest ash (0,49%) content and amount of condensed tannin (13,89%) are extracted from heartwood, followed by total wood, and sapwood, respectively. The test panels manufactured from sapwood have the smoothest surface (7,49 µm (R a ) , 48,86 µm (R y ), and 35,12 µm (R z )) and the lowest contact angles (67,8°), while the roughest surface (14,20 µm (R a ) , 68,05 µm (R y ), and 50,02 µm (R z )) and highest contact angle (96,9°) are obtained from the panels of heartwood. The thickness swelling (19,88%) and formaldehyde emission (7,28%) values of the panels manufactured from heartwood are significantly lower than the panels manufactured from the total wood and sapwood. The highest modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond (IB) values are observed on sapwood, respectively, 15,60 MPa (MOR), 2201 MPa (MOE), and 0,523 MPa (IB). These mechanical strength values (MOR, MOE, and IB) are followed by total wood, and the heartwood, respectively. Surface smoothness and wettability of the particleboards manufactured from sapwood are better than those of total wood and heartwood.Maderas. Ciencia y tecnología 21 (4): 511 -520, 2019 Universidad del Bío-Bío 512 Akbulut, T. 1995. Effects of various factors on the properties of particleboard, Ph.D. Thesis, Istanbul University, Faculty of Forestry, Istanbul, Turkey. ˂https://tez.yok.gov.tr/UlusalTezMerkezi/tezSorguSonucYeni. jsp>. (Access 07/06/2017). Akyuz, K.C.; Nemli, G.; Baharoglu, M.; Zekovic, E. 2010. Effects of acidity of the particles and amount of hardener on the physical and mechanical properties of particleboard composite bonded with urea formaldehyde. Journal of Adhesion and Adhesives 30(3): 166-169. Atac, Y. 2009. Examination some softwood and hardwood trees interms of paper properties of their sapwood and hearthwood. Ph.D. Thesis, Bartin University, Bartin, Turkey. ˂https://tez.yok.gov.tr/UlusalTezMerkezi/ tezSorguSonucYeni.jsp>. (Access 07/06/2017). Atar, I.; Nemli, G.; Ayrilmis, N.; Baharoglu, M.; Sari, B.; Bardak, S. 2014. Effects of hardener type, urea usage and conditioning period on the quality properties of particleboard. Materials and Design 56: 91-96. Ayrilmis, N.; Buyuksari, U.; Avci, E.; Koc, E. 2009. Utilization of pine cone in manufacture of wood based composite. Forest Ecology M...