Azaarenes were characterized in several Recent and ancient sedimentary samples and anthropogenic source materials by glass capillary gas chromatography using nitrogen-specific detection, gas chromatography/mass spectrometry, and probe distillation/low voltage mass spectrometry. In lake surface sediments and street dusts, unsubstituted azaarenes containing three to five aromatic rings predominate over the more numerous alkyl homologues. In contrast, azaarenes in fossil organic matter have a much more complex composition, with alkyl azaarenes much more abundant than unsubstituted molecules. In this respect, the azaarenes resemble the PAH composition of these samples. Diazaarenes were apparently also present. An anthropogenic origin for the aza aromatics in the surface sediments is indicated, with street dust as a likely source for some of the sedimentary azaarenes. There is no evidence that natural combustion processes contribute azaarenes to Recent lake sediments.