Abstract: Güre geothermal field is located in NW Anatolia within the boundaries of Balıkesir. This study attemptsto determine the geologic and hydrogeochemical characteristics of the field and close surroundings and theircorrelation with active tectonism. The basement of Güre geothermal field is rocks of the Paleozoic-age KazdağGroup. Above the basement, the Triassic-age Karakaya Formation lies above an unconformity. The CretaceousÇetmi melange tectonically overlies this basement. The Upper Oligocene-Lower Miocene Hallaçlar volcanics andOligo-Miocene granodiorites were emplaced by cutting all older units. Quaternary alluvium unconformably overliesall units in the study area. The Güre geothermal field located on the east section of the Edremit Fault Zone, markedas an active fault on the Active Fault Map of Turkey, is controlled by a nearly ENE-WSW oriented, south-dippingnormal fault. In the instrumental period from September 2013 to August 2014, nearly 12 earthquakes occurred inthis region and close surroundings with M=3.0 or more. Geothermal water from four hot-water wells in the Güregoethermal field had monitoring studies performed in 12 different periods from 21.09.2013-16.08.2014. Physicochemical measurements and experimental studies of water from Güre geothermal field were compared simultaneousto earthquakes in the region. Before and after earthquakes changes were observed in these thermal waters, especially T0C, pH and EC values. Additionally chemical analysis of the water identified increases or reductions in manyelemental levels, especially Cl-, Na+ and SO4-2. It was concluded that these variations were directly related to theactive tectonic regime in the region.