A method for the determination of aromatic amines in mainstream smoke of mechanically, smoked cigarettes has been developed. The fast reaction of aromatic amines with other smoke constituents formed during the combustion process can be significantly reduced by the addition of an excess of p -toluidine to the acidic collecting solution. From this point the p -toluidine as intercept reactant immediately stabilizes the originally formed amines and results in high recovery rates. The method allows the gas chromatographic determination of aniline, o - and m - and p -toluidine. 1- and 2-aminonaphthalene, 2- and 4-aminobiphenyl, 1-, 2- and 4-aminofluorene, 3-aminofluoranthene, 1-aminopyrene and 6-aminochrysene in the mainstream smoke of a single cigarette. d₅-Aniline, d₇-2-aminonaphthalene, d₉-4-aminobiphenyl as well as fluoranthene and chrysene were used as internal standards. By this new method, 21 ng of 2-aminonaphthalene and about 3,6 ng of 4-aminobiphenyl have been detected in the mainstream smoke of a common blend filter cigarette. As expected, these contents were higher in cigarettes manufactured from alkaline tobacco.