Polycyclic aromatic hydrocarbons (PAHs) are organic compounds consisting of fused or condensed benzene rings that mostly have adverse environmental effects. The interaction of PAHs with water molecules plays an important role in understanding their aqueous behavior. Despite the ubiquitous presence of such compounds in nature, experimental data for the solvation properties of PAHs are rarely available or incomplete because of their extremely low solubility in water, yet conventional thermodynamic methods to estimate such properties are often unreliable. Here, we demonstrate that the hydration free energies and the solvation structures of PAHs can be quantitatively predicted by a combination of the first principles and the classical density functional theory calculations. The theoretical procedure may serve as a useful alternative to the missing experimental data and, importantly, provides microscopic insights into absorption and degradation of PAH compounds in aqueous environments.