The objective of this work was to present the plan and methods of an epidemiological study of the risk of death from cardiovascular diseases in males and females of working age exposed to risk factors related to this group of diseases. The survey covered random samples of the general population, 20-64 years of age, living in areas of two regions (voivodeships) as well as families of all the decreased from cardiovascular diseases, coming from the same areas. Data on risk factors characteristic for this group of diseases in the general population and in the decreased were obtained. The method of assessment of death risk in persons exposed to given factors is presented. In the method, a standardized mortality ratio (SMR) was used. Organization of the study and its results will be discussed in Section II of this work.