The Late Cenozoic geodynamic evolution of Simav (Kutahya) and surroundings was determined by dating active tectonic structures in the region (Simav Fault and Simav Detachment Fault) and granitic and volcanic rocks of the Egrigoz Magmatic Complex. Additionally it was revealed that the currently normal Simav Fault, in previous periods acted as a strike-slip fault according to dating studies of fault planes and field observations. Dating of the fault planes along the Simav Fault determined that initiation of the Simav Fault occurred in the interval between 19.3-26.1 Ma. In this period the Simav Fault demonstrated strike-slip fault behavior in a compressional regime. The results of dating studies of the Egrigoz and Koyunoba Plutons (21.9-26.3 Ma) reveal that the unroofing of these plutons was related to the Simav Detachment Fault (20.0-27.4 Ma). Additionally the presence of volcanism in the time period was identified (7.1-21.3 Ma). The Simav Fault which displayed previous strike-slip character currently has listric normal fault behavior after a tectonic regime change in the Plio-Quaternary. The transition from extensional-compressional regime to a regional extensional regime and cause of the tectonic regime change is thought to be related to the complex subduction process (slab-pull and and roll-back) between the African Plate and Anatolian Plate in the Eastern Mediterranean.