In this study, effect of tree species on some physical properties of M edium D ensity F iberboards (M DF), such as a ir dry density, thickness swclling (2 and 24 hours), and w ater absorption (2 and 24 hours), m anufactured from furnishes of oak (Q uercus ro b u r), beech (Fagus orientalis), pine (Pinus nigra), an d a m ixture of these species (a m ixture of 40 percent oak, 40 percent beech, and 20 p e rc e n t pine furnish) was investigated. Ali physica! p ro p erties w ere tested according to ISO stan d ard s. Analysis o f variance (at a 95 percent confidence level) an d m ultiple-range test (Duncan) w ere used to evaluate the effect of tree species on physical p ro p e rtie s of M D F. F ro m th e tests p erfo rm ed , it w as concluded th a t physical properties o f th e panels m ade from pine furnish are b e tte r th a n th o se o f pan els m ad e fro m o ak , beech, a n d m ixed fu rn ish .