In this study, effects of specific gravity (SG), shelling ratio, wood species, and pressure on the formaldehyde content, physical (SG and thickness swelling (TS)), and mechanical properties (modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond (IB) strength) of particleboard were examined. The best manufacturing parameters were determined for E-1 grade particleboard manufacturing from urea formaldehyde (UF) adhesive. Based on the findings of this study, increasing of SG, shelling ratio, and pressure increased the formaldehyde content. Particleboard made from particles consisting higher amount of beech particles had lower formaldehyde content than that of panel from particles consisting higher amount of pine particles. (C) 2005 Elsevier Ltd. All rights reserved.