The objective of this study was to investigate the effects of heat treatment on the physical and mechanical properties of sessile oak (Quercus petraea). Samples were exposed to three temperature levels of 120°C, 150°C, and 180°C for time periods ranging from 2 to 10 hours. Modulus of elasticity, modulus of rupture, compression strength parallel-to-grain, hardness, impact bending, tension strength, swelling in three sections, and surface roughness of the samples were evaluated. Based on the findings in this study, the results showed a significant difference between properties of control samples and heat-treated samples (P = 0.05). Mechanical properties of the samples were adversely influenced as a result of heat treatment; however, surface quality and dimensional stability of the samples improved with heat treatment. Changes in properties of the samples were more pronounced as temperature and exposure times were increased.