OBJECTIVES: Obesity, hypertension and dyslipidemia (low HDL-cholesterol, high triglycerides) are known risk factors (RF) for the development of cardiovascular diseases and diabetes mellitus type 2 (DM). The aim of the study was to develop a decision analytic model as a tool to assess the cost-effectiveness of treatment options of obesity and associated cardiovascular risk factors. METHODS: As part of the German Metabolic and Cardiovascular Risk Project GEMCAS a decision analytic model from the German payer's perspective was developed. RESULTS: The model has a cycle length of one year and consists of nine health states (HS): (HS1) DM without complications and no further RF; (HS2) DM without complications and one further RF (HS3) DM without complications and 2-4 further RF (HS4) DM with microvascular complications (HS5) DM with macrovascular complications (HS6) healthy (HS7) 1-4 RF (HS8) post myocardial infarction or stroke (HS9) death. Annual costs have been assessed for each health state as well as for transitions due to myocardial infarction or stroke: (HS1) 626 Euro (HS2) 794 Euro (HS3) 962 Euro (HS4) 6.276 Euro (HS5) 3.633 Euro (HS6), 0 Euro (HS7), 336 Euro (HS8) 1.710 Euro, transition costs for myocardial infarction are 4.560 Euro and for stroke 4.780 Euro. Target population has a defined risk profile and transition probabilities are calculated using the Framingham Risk Equation for myocardial infarction and stroke. Additionally an independent effect of obesity according to the INTERHEART study was assumed. The development of DM was calculated based on the risk equation from San Antonio Heart Study. CONCLUSION: The presented model is a valuable tool to assess the cost-effectiveness of different treatments options and can be adopted for new interventions easily.