Renewable chemicals are of growing importance in terms of opportunities for environmental concerns over fossil-based chemicals. Lignocellulosic biomass can be converted into energy and chemicals via thermal and biological processes. Among all the transformation processes available, fast pyrolysis is the only one to produce a high yield of a liquid-phase product called bio-oil or pyrolysis oil. Bio-oil is considered to be a promising substitute for phenol in phenol formaldehyde (PF) resin synthesis. In this work, bio-based phenolic resins have been formulated, partially substituting phenol by bio-oils from two Canadian whole-tree species. The new resins are produced by replacing 25, 50, and 75% of phenol with bio-oil for each species (three bioresins per species). The aim of this study is to synthesize renewable resins with competitive price and satisfactory quality. The results obtained have shown that substitution degree up to 50% provided reactivity and performance equal or superior to the pure PF resin. They also present a good storage stability, improved shear strength, and thermal stability comparable to the pure PF. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 40014.