This research paper studies the influence that the number of plies has on the identification of the mechanical properties of poplar Laminated Veneer Lumber (LVL) from tensile tests such as its stiffness. LVL poplar specimens were prepared with different ply configurations and subjected to uniaxial tensile tests. Both longitudinal and transverse stiffnesses were characterized in this research. The results show that the ply configuration influences the mechanical properties. The influence of the glued faces, the presence of lathe checks, and the compression ratio of veneers were studied during the manufacturing of the LVL. All these results provide valuable information for the design and optimization of laminated wood structures. An analytical modelling strategy is proposed to account for the effect of ply numbers, ply orientations, the compression ratio of veneers and the glue used on the stiffness of poplar laminate both in longitudinal and transverse directions.