Dementia is one of the three diseases that cause the highest number of healthy years of life lost. Due to the aging of the population, this disease group represents an increasing burden for the health and long-term care system in Austria. As a basis for planning and evaluating interventions, it is important to know the magnitude of costs attributable to dementia, as well as in which areas these costs arise. For this purpose, we conduct a cost-of-illness study that captures direct, indirect as well as intangible costs. In addition to a cross-sectional view, the costs are also determined in a life-cycle model.