The construction of dams on rivers feeding deltas has caused rapid shoreline retreat of many deltas around the world. To show that the retreat has been due to anthropogenic effects, it is very important to observe the natural shoreline changes before the dams effects on a delta. This study investigated shoreline changes in the Seyhan Delta in the Eastern Mediterranean from 1950 to 2018 employing long-term Landsat satellite images and aerial photographs. The results indicated that the shoreline accreted nearly +131 m with a maximum rate of + 22.9 m yr(-1) from 1950 to 1956. In this period an area of +322 071 m(2) was added to the delta. Contrary to this, following the construction of the Seyhan Dam in 1956, the Seyhan Delta lost a total area of -4 039 251 m(2) from 1956 to 2018. The shoreline retreated -2293 m at the river mouth, with a maximum rate of retreat of -37 m yr(-1). The major cause of this retreat is the trapping behind the Seyhan Dam of sediments transported by the Seyhan River. In the future, it is expected that the shoreline will retreat even more rapidly from causes such as the construction of further planned dams, deltaic subsidence and rising of global sea level. This situation will have a great impact upon wetland areas and upon agricultural and tourism areas and structures in the delta.