The investigation of complex diseases such as strokes, Alzheimer’s disease, dementia or multiple sclerosis is only possible by considering the interaction between genetic and environmental factors. Genetic examinations are carried out in cohort or case / control studies and require a particular know how and infrastructure in the following fields: Genetic Epidemiology, Epidemiology, Molecular Biology, Bioinformatics and Statistics, as well as a close cooperation with hospitals. The major aim of this research is to identify genetic determinants of neurological diseases as well as to examine their role in the development of a disease together with environmental, lifestyle and social factors. We assume that these results will enable us to better understand the pathogeny as well as to precisely define high risk groups in the future. Moreover this will path the way for individual prevention and therapy. Thereby genetic epidemiology has a leading role in the development of individualised medicine. The recent developments in biotechnology and bioinformatics have facilitated genome-wide association studies. In these studies millions of polymorphisms are determined and their association to diseases is systematically evaluated. The results of these studies have led to the identification of new reasons for Diabetes Mellitus or Macula Degeneration. As these studies have an enormous potential in discovering unknown reasons for the development of diseases, numerous universities of high reputation have established genetic-epidemiological research units and departments. The Institute of Molecular Biology and Biochemistry and the Department of Neurology have already cooperated for years concerning genetic-epidemiological research with a particular stress on neurodegenerative and vascular age-associated cerebral changes. This research uses structural and personal resources of both units. This cooperation has already led to numerous high-ranking publications with a total impact factor of > 300 out of grants such as: FWF P13-180MED (R.Schmidt & H.Schmidt) - MRI White Matter Lesions: Genetics, Progression, Cognition; OeNB Jubiläumsfonds 7776 (H.Schmidt, F.Fazekas, R.Kleinert) - ApoE in Microangiopathy-Related Cerebral Damage; FWF P15440 (H.Schmidt) – Promoter Haplotype Dependent Expression of Angiotensinogen; FWF P20545-B05 (H.Schmidt, R.Schmidt, F.Fazekas) - Genetic Determinants of Cerebral Small Vessel Disease. Research Portal We are well prepared for the future of genome-wide association studies, which will be formative during the coming years.