alpha, beta-Unsaturated carbonyl compounds are industrially important compounds, ubiquitous in the environment and are formed endogenously. They interact with proteins and enzymes. Genotoxicity was found in eucaryotic cells and some compounds were carcinogenic. Unsaturated carbonyl compounds are considered to play an important role in human cancer. Insufficient and contradictory results were reported on mutagenicity. We demonstrated a clear mutagenic potential for these compounds and have shown interference of their bacterial toxicity with an adequate testing. Structure-mutagenicity relationships were confirmed by the results of the SOS-chromotest. The compounds induce DNA-strand breaks. However, we did not find indications for cross linking. With mutagenic alpha, beta-unsaturated carbonyl compounds we isolated and characterized 1,N2-cyclic deoxyguanosine adducts, 7,8-cyclic and 7-linear guanine adducts as well as 1,N2-7,8-biscyclic adducts and 1,N2-cyclic, 7-linear bisadducts. Reactivity of these compounds towards nucleosides runs in parallel with their mutagenic potential. Mutagenic and carcinogenic activities most probably depend on these reactions with DNA, and DNA adducts can be utilized as indicators for the role of these compounds in human carcinogenicity.