1-Octanol/water partition coefficients in infinite dilution of several phenol, indole, biphenyl, and naphthalene derivatives, a few polycyclic aromatic compounds, and some polyfunctional haloaromatics determined by using reversed-Phase high-Performance liquid chromatography (RP-HPLC) are reported. These data may be used for estimating the ecotoxicological impact of those compounds identified in brown coal liquids (e.g., hydroxyaromatic compounds), as well as for the extension of methods to correlate and Predict Partition coefficients in organic/aqueous liquid phases.