In this study, effect of tree species on mechanical properties of Medium Density Fiberboards (MDF) manufactured from furııishes of oak (Quercus robur), beech (Fagus orientalis), pine (Pinus nigra), and a mixture of these species (a mixture of 40 percent oak, 40 percent beech, and 20 percent pine furnish) was investigated. Tests were made on specimens conditioned at 2 0 + 2 °C and 6 5 + 5 percent relative humidity. Analysis of variance and multiple-range test (Duncan) vvere carried out to evaluate test results at a 95 percent confidence level. According to the results o f this research, except for Janka hardness, the other mechanical properties of the panels made from pine furnish vvere better than those of panels made from oak, beech, and a mixture of these species furnish.