The acetylation process involves chemical reaction between acetic anhydride and wood, which results in esterification of accessible hydroxyl groups in the cell wall, with formation of the by-product acetic acid. Acetylation of wood has been widely studied during the past decades, and several experimental studies have proven it to be effective in reducing the hygroscopicity of wood resulting in improved dimensional stability and fungal resistance. For load-bearing timber structures used in outdoor environment, the combination of acetylation and engineered wood products gives the possibility to manufacture more durable timber elements with remarkable dimensional stability without negatively affecting the mechanical properties. The objective of this study concerns the mechanical properties of both acetylated and untreated birch plywood loaded parallel to the face grain direction. The test results are compared and discussed.