Four tar-contaminated sites in Germany (Lunen, Castrop Rauxel, Stuttgart and Wulknitz) were investigated and 42 polycyclic aromatic compounds (PAC) were detected in significant concentration ranges including polycyclic aromatic hydrocarbons (PAH), substituted PAC, heterocyclic PAC containing nitrogen, sulphur and oxygen as well as their metabolites. A similar composition and pattern of PAH heterocyclic PAC and metabolites were found in corresponding groundwater samples. Identification and quantification were performed using liquid-liquid extraction and analyses with gas chromatography - electron impact - mass spectrometry. Detailed investigation (in Castrop Rauxel, Germany) showed that the distribution of non-polar compounds can only be detected close to the source of contamination, whereas the distribution of more polar compounds and degradation products is more widespread downstream of an aquifer.