This study was designed to determine some mechanical properties such as modulus of rupture (MOR) and modulus of elasticity (MOE) of wood treated with some environmentally-friendly fire-retardant boron compounds. Sodium perborate (SP) boric acid, (BA), and borax (BX) were used as boron compounds. Wood specimens were prepared from Calabrian pine (Pinus brutia Ten.) and beech (Fagus orientalis Lipski) wood. Before MOR and MOE tests, wood specimens were impregnated with aqueous solutions (1, 2, 3, 4, 5, and 6 %) of berates according to ASTM D 1413-76.