Posttraumatic Stress Disorder (PTSD) is a major health problem in South Eastern Europe (SEE). Available treatment options are not efficient enough and the course is often chronic. Little is known about molecular mediators and moderators of pathogenesis and therapy. Genetic and epigenetic variation may be one central molecular mechanism. We therefore established a consortium combining clinical expertise on PTSD from SEE countries Bosnia-Herzegovina (Sarajevo, Tuzla and Mostar), Kosovo (Prishtina) and Croatia (Zagreb) with genetic and epigenetic competence from Germany (Würzburg) in 2011 within the framework of the DAAD (Deutscher Akademischer Austauschdienst)-funded Stability Pact for South Eastern Europe. After obtaining ethical votes and performing rater trainings as well as training in DNA extraction from EDTA blood between 2011 and 2013, we recruited 747 individuals who had experienced war-related trauma in the SEE conflicts between 1991 and 1999. 236 participants had current PTSD, 161 lifetime PTSD and 350 did not have and never had PTSD. Demographic and clinical data are currently merged together with genetic and epigenetic data in a single database to allow for a comprehensive analysis of the role of genetic and epigenetic variation in the pathogenesis and therapy of PTSD. Analyses will be done to a great degree by PhD students from participating SEE centers who in addition to participation in the project had an opportunity to take part in spring and summer schools of the DFG (Deutsche Forschungsgemeinschaft) funded Research Training Group (RTG) 1253 and thus meet PhD students from Germany and other countries We are confident that our project will not only contribute to a better understanding of genetic and epigenetic mechanisms of PTSD as a basis for future individualized and personalized therapies, but also to the academic development of South Eastern Europe.