AbstractThe vapour pressure (VP) is an important physical property of organic compounds for the description of fate and distribution of xenobiotics in the environment. This property was measured for 30 polycyclic aromatic hydrocarbons (PAH) and formulas for VP based on molecular weight and topological indices, respectively, were derived using the technique of Kubinyi and as a second step by regression analysis. A formula for the 30 PAH, considered here, is given.Therein the VP is related to the information theoretical index IdWmean and with a chain‐connectivity index. More specific results are derived for three groups of PAHs. The robustness of the equations is tested by bootstrap analysis. In addition a formula is discussed, which is based on four different incremental factors, a method widely used in physical organic chemistr