In this study, it was aimed to use of bio-oil as an alternative to petroleum-based phenol in the production of phenol-formaldehyde (PF) resin used for making exterior plywood. Bio-oil obtained from pine wood sawdust using a vacuum pyrolysis reactor at 500 degrees C. The PF resol resins were produced by substituting up to 20 wt% of phenol with bio-oil by modifying the chemical synthesis process. FT-IR analysis was performed to characterize the organic functional groups in the bio-oil modified PF resins. In comparison to the commercial and lab-made PF resins, the bio-oil modified PF resins were found to have larger average molecular weights, higher polydispersity indices, and shorter gel times. Six different types of plywood panels were produced from the experimental PF resins which were commercial PF resin, lab-made PF resin, and PF resins modified with bio oil of 5, 10, 15 or 20 wt% contents, respectively. Plywood specimens produced with the PF resin modified with bio-oil up to 20 wt% had better tensile shear strength (wet condition), modulus of rupture, and modulus of elasticity in bending as compared to the commercial and lab-made PF resins.