A Monte Carlo simulation model is presented which allows an assessment of the costs for coronary heart disease (CHD) (from a social security perspective) to be made over a time interval of 10 years. The difference between a CHD population and a normal population is calculated whereby the CHD population corresponds in terms of age and gender distribution to a German population with existing hypercholesteremia. The data were generated from the results of the German Cardiovascular Prevention Trial (DHP), a population was determined which represents the age group of the 45- to 65-year-old German population. Both direct as well as indirect costs were taken into account. The model simulates 2 submodels: 1. CHD is already present in the observed population. 2. A proportion of the observed cases of hypercholesteremia develop CHD over a time interval of 10 years, whereby normal distribution of the events is assumed. From the social security perspective, the cumulative costs of CHD for the observed age group who already have CHD amount to approximately 59 billion DM in 10 years (see Table 4). On the assumption that CHD develops during the course of these 10 years and that the population does not already present with CHD at the start of the simulation model, the costs are calculated to be about 41 billion DM (see Table 3). Numerous sensitivity analyses were carried out which showed that the assumption of the direct costs per case/year were highly sensitive (see Figure 1). The special advantage of the model is the perspective chosen, since social security is considered as a whole and interactions between individual branches of social security become transparent.