Abstract: Kuşadası Bay, which is controlled by active normal faults, is located in an evolving graben in the westof the Western Anatolian Extension System. Gümüldür Fault (GF), which restricts Kuşadası Bay to the north, hasapproximately 30 km long, fragmented structure between Ürkmez and Ahmetbeyli. GF, which strikes N (50o-55o)W direction, forms a sharp morphological escarpment between Ürkmez and Ahmetbeyli starting from Paleozoicbasement rocks to Quaternary alluvium units. The dip angle of the fault planes increases to the west (40o-85oSW),and the fault is a dip-slip active normal fault with convex structure and geometry toward the northeast. To unravelthe Quaternary activity of Gümüldür Fault and the evaluation of the regional uplift, morphometric and kinematicanalysis was performed for the first time on the fault that includes well-preserved geomorphological markers.Quantitative measurement of morphometric indices such as mountain front sinuosity (Smf: 1.13-1.56), valley floor  width to height ratio (Vf: 0.10-1.00), percentage faceting Lf/Ls ([L: 4.75-88.35, S: 0.12-9.30]), asymmetry factor (AF:19-78 ), basin shape geometry (Bs: 1.05-5.98), stream length gradient (Hack) index (SL: 25-6094.44), hypsometriccurve and hypsometric integral (HI: 0.16-0.53) and rock strength and climate parameters indicate that the footwallof the GF has been uplifting toward the west with more than 0.5 mm per year. According to kinematic studies ofthe GF, which is geometrically composed of three parts, the region developed under the control of an extensionalregime oriented NNE-SSW. If it is broken in seperate segments, it has the potential to produce earthquakes witha magnitude of 6.12, 6,45 and 5.78, respectively. If considered as a single segment, it has the potential to produceearthquakes with a magnitude of 6.81 in Kuşadası Bay. For this reason, trench-based paleoseismological studies areneeded to reveal the past activity of Gümüldür Fault and to determine the seismic hazard level in the region.