The purpose was to study the precision and the separation efficiency of the analytical methods which are currently discussed for the sampling and the analysis of polycyclic aromatic hydrocarbons (PAH) in the exhaust of automobiles. The sampling of the PAH is done by condensing the total exhaust gas flow. The PAH collected are concentrated by known liquid-liquid extractions, purified by silica gel and separated into fractions using Sephadex.Two quantitative analytical methods are used, the advanced technique of glass capillary gas chromatography and thin-layer chromatography coupled with in situ fluorescence spectrometry. The results of these chromatographic methods correlate within an error of 10% for both gasoline and diesel exhaust samples. The PAH contents in the exhaust gas of several diesel and gasoline cars are compared for different driving cycles. The corresponding PAH mass emissions from diesel and gasoline cars are of the same order of magnitude.