The Canakkale Strait (Dardanelles) is a water passage connecting the Aegean Sea and the Marmara Sea. Its NE/SW trend is interrupted by a north-south bend between Eceabat and Canakkale. The width of the Strait varies from 1.35 to 7.73 km, the narrowest part located between Canakkale and Kilitbahir. The average depth of the Strait is approximately 60 m; the deepest part reaches more than 100 m. The aim of this study is to determine the locations of fresh water discharge into the Canakkale Strait. For this purpose, 52 sample points were selected in the study area. The temperature, pH and salinity were measured at different depths of water in the Canakkale Strait (1, 5, 10, 20 and 30 m). A Geographic Information System (GIS) was used to create a tabular and spatial database, with the aim of integrating the physical properties in the Canakkale Strait. The results of this study show that discharge of fresh water is seen in four locations on the southeastern coast between Dardanos and Canakkale, and that the Aegean Sea and Marmara Sea water are mixing between Canakkale and Kilitbahir. In the future, these sources of fresh water may be needed as population increases in the region. However, water pollution in the Canakkale Strait may limit the use of this fresh water.