Abstract: Kütahya Basin which is located near the northeast boundary of the Western Anatolia Extension Regionis a depression area that extends in WNW-ESE direction. Southern margin of the basin is bounded by adistinct fault morphology called Kütahya Fault Zone. Geological, geomorphological and geophysicalstudies on the Kütahya Fault Zone show that this zone consists of 5 different fault branches. Total length ofthe mapped fault zone is about 22 km in N50-70W direction. Paleoseismological and archeoseismologicalstudies show that there are at least two surface rupturing earthquakes during the last 8000 years. First  earthquake was occurred around 6000 BC and the last one was around 1800 B.C. after which the SeyitömerTell was abandoned. Thus, this study indicates that the Kütahya Fault Zone has produced destructiveearthquakes during Holocene and considering the length of the fault zone, it is possible to suggest that thefault zone has earthquake potential at least 6.5 magnitude.