The variations in anatomical characteristics namely fibre length, fibre diameter, fibre lumen width and cell wall thickness of Tectona grandis wood age 15, 20 and 25-year old respectively were investigated. Six trees from each even aged stand and similar class diameter selected from Edo State Forestry plantations were used for the study. Wood samples were systematically collected from the outer, middle and inner wood sections of the radial and longitudinal positions at 10, 50 and 90% of the tree height. The mean values of fibre length were 1.45, 1.73 and 1.96 mm; fibre diameter were 26.79, 29.47 and 32.83 μm; fibre lumen width were 18.17, 15.60 and 14.17 μm while the mean values for fibre wall thickness were 5.87, 7.89 and 9.80 μm for 15, 20 and 25-year old Tectona grandis wood respectively. Fibre length, fibre diameter and cell wall thickness increased with increase in age while fibre lumen width decreased with increase in age. However all the anatomical characteristics examined in this study increased from innerwood to outerwood but decreases from the base to top. Analyses of variance used for mean separation were significant (p <0.05).