Initiated in 1975, the Eberbach/Wiesloch Study is a prospective preventive study modeled after the Cardiovascular Comprehensive Community Central Programme of the WHO, with the aim of lowering the incidence of cardiac infarctions in a population representative of that of the Federal Republic of Germany. Part of the study is devoted to a description of smoking habits, and in particular, of the effect of cigarette smoking on plasma lipid and lipoprotein levels. Important components of this investigation were the inclusion of plasma levels of cotinine (a stable metabolite of nicotine and the only precise parameter of cigarette consumption), as well as the correlation of cotinine with other plasma parameters. Not only are these studies unique in the Federal Republic of Germany, but they also provide significant insight into the development of arteriosclerosis in connection with the established risk factors of smoking and hyperlipidemia. The data collected point to a considerable influence of smoking behavior on plasma lipid protein parameters.