According to WHO, 20.1% of over 17-year-olds are obese, which is double the share compared to 30 years ago. Under the assumption that this trend continues, WHO estimates the share for Austria to be 25% in 2030. Raised BMI has been found to be a major risk factor for various non-communicable diseases such as cardiovascular diseases, type II diabetes, gout, caries, arthrosis and other musculoskeletal diseases, colon cancer and other forms of cancer. Despite its significance for the Austrian public health system and the fact that the corresponding figures would be required for any economic evaluation in the field, there is no study that calculates the costs of obesity in Austria. Aiming to close this gap, we conduct a cost-of-illness study to determine direct medical, direct non-medical, and indirect costs of obesity in Austria. The starting point of the study is a review of the literature on relative risks of health consequences of obesity. In addition to a cross-sectional view, we draw on a specially developed model that allows for incorporating costs arising over the entire life cycle.