On the Drina basin pilot area located between Serbia and Bosnia Herzegovina experts from the Geological Survey of the Republic of Srpska-Zvornik, Federal Institute for Geology - Sarajevo, University of Belgrade - Faculty of Mining and Geology, and the Mining and Geological Survey of Hungary had a 2 days joint mission, where they collected thremal water samples from Bogatic, Dvorovi and Slobomir for further detailed hydrogeochemical analyses. The main aim is to gain information on the origin (recharge areas) and age of the thermal water in this region.