This work provides new experimental data of speed of sound and density for seven pure components of pyrolysis bio-oil at atmospheric pressure for several phenols (phenol, o-, m-, and p-cresol), two phenolic ethers (2-methoxyphenol and eugenol) and one phenolic ester (methyl salicylate) at temperatures of (288.15 to 343.15) K. Densities and sound velocities are correlated with the Prigogine-Flory-Patterson (PFP) model. The properties are well described with the PFP model showing a better performance for the denser substances. The relation between density and speed of sound evidence the complex thermophysical behavior of substituted phenols.