The Çameli basin of southwestern Turkey contains terrestial clastics and lacustrine sediments ranging in age from Vallesian (Late Miocene) to Villanian (Late Pliocene). The Çameli formation consisting of alluvial fan, fluvial and lacustrine facieses is the prominent unit in the basin. The alluvial fan facies is at the base of the basin fill and grades into the fluvial facies basinward. Its contact with the basin-margin bedrock is generally a faulted contact. It is, however, locally an erosional unconformity representing depositional backlap. The basin also contains strike-slip fault planes that cut across the basin fill. The fault planes of these faults are well observed in the vicinity of the ancient town of Cibyra where a 50 cm left lateral strike-slip is previously reported based on the destroyed stair steps of the town's stadium. Historical seismicity records indicate two important earthquakes in the Cıbyra area; the first one in 23 AD and the second in 417 AD. Historical seismic activity is also evidenced by field observations and fault plane solutions of the micro earthquakes occurred in the area. Field relationships suggests that the fault is Early Pleistocene or later in age. However, timing of the initiation this fault zone needs to be further investigated. The strike of active strike-slip faults observed in the Çameli basin coincides with the strike of the Fethiye - Burdur strike-slip fault zone (FBFZ) of southwestern Turkey. The FBFZ is generally recognized as the inland prolongation of the left-lateral Pliny transform zone that is the eastern continuation of the Hellenic subduction zone. Therefore, we suggest that the left-lateral fault zone that cuts across the Çameli basin is part of the FBFZ.