Abstract: This study was carried out to determine the effect of the impregnation process on screw withdrawal strength in some wood materials. In this regard, the samples prepared from the woods are most commonly used in the furniture industry such as Oriental beech (Fagus orientalis lipsky) (I), European oak (Quercus petreae lipsky) (II) and Scotch pine (Pinus sylvestris lipsky) (III) were impregnated with borax (Bx), boric acid (Ba), borax+boric acid (Ba+Bx), Imersol-aqua (Ia) and Timbercare-aqua (Ta) in accordance with ASTM D 1413, TS 344 and TS 345. The screws 3.5x50 mm (S1) and 4x50 mm (S2) that were connected to the cross surfaces of the impregnated samples were subjected to withdrawal test in accordance with TS EN 13446. As a result, the highest screw withdrawal strength was obtained in European oak (3.675 N mm-2) and the lowest in Scotch pine (2.693 N mm-2) for the wood type. The highest screw withdrawal strength was obtained in S2 (3.363 N mm-2) and the lowest in S1 (3.222 N mm-2) in for the screw diameter. The highest screw withdrawal strength was obtained in II + Bx + S1 (4.193 N mm-2) and the lowest in III + Ba + S1 (2.251 N mm-2) for the interaction of wood type, impregnation material and screw diameter. So, the impregnation process increased the screw withdrawal strength. It can be said that, in the applications, where the pieces are impregnated with Bx and connected with V1 at the cross surface shall display the highest strength.