The effects of density on variations in the mechanical properties of plantation grown Tectona grandis wood aged 15, 20 and 25-year were examined. Six trees were selected from each age class from the Edo State Forestry plantation sites located within the Forest Reserves. Wood samples were collected from innerwood, middlewood and outerwood at 10, 50 and 90% of the tree merchantable height. The mean density values on oven dry weight and volume basis were 480, 556 and 650 Kg m-3, moduli of rupture were 76.86, 103.95 and 134.69 N mm-2, moduli of elasticity were 6846.92, 9920.54 and 12845.57 N mm-2, compressive strength parallel to grain were 43.74, 58.47 and 75.36 N mm-2 for age 15, 20 and 25-year old Tectona grandis wood. Wood density and mechanical properties increased with increase in age. Whereas wood density and mechanical properties increased from pith to bark, they however decreased from base to top at any particular height. The correlations between density and MOR, density and MOE, density and CS were significant (p < 0.001). Therefore wood density can be used in predicting the mechanical properties of Tectona grandis wood.