The objective of this study was to investigate the feasibility of using the bio-oil generated from the Mississippi State University's (MSU's) fast pyrolysis process as part of a polymeric diphenylmethane diisocyanate (pMDI) binder system for flakeboard production. The bio-oil was obtained from the pyrolysis process of pine wood (Pinus spp.) at the MSU bio-oil laboratory. The effect of the resin content and the pMDI to bio-oil ratio on the physical and mechanical properties of the flakeboards was examined. The properties include internal bond, modulus of rupture, modulus of elasticity, thickness swelling, and water absorption. The effect of adding acetone into the pMDI/bio-oil resin on the properties of flakeboards was also investigated. The results showed that the incorporation of acetone reduced the viscosity of the adhesive by up to 67 percent, from which the efficiency for resin spraying on the flakes was improved. The higher the bio-oil content, the lower the mechanical strength of flakeboard obtained. However, the pMDI resin with a bio-oil content of 25 percent showed comparable bonding properties to those of pure pMDI resin.