Chemical and isotopic compositions of three hot springs and one cold spring in the Kirkgecit geothermal field, located 15 km southwest of Canakkale-Biga in the northwest of Turkey, were monitored five times during 2005 and 2007. The physico-chemical characteristics of the hot springs are average discharge 3-3.5 L/s, surface temperature 45-52A degrees C, pH 8.9-9.3, and electrical conductivity (EC) 620-698 mu S/cm. The cold spring has a temperature of 12-13A degrees C, pH 7.5-8.3, and EC 653-675 mu S/cm. The hot waters are Na-SO4 type, whereas the cold water is Ca-HCO3 type. Chemical geothermometers suggest that the reservoir temperature is around 80-100A degrees C. The isotopic data (oxygen-18, deuterium and tritium) indicate that the thermal waters are formed by local recharge and deep circulation of meteoric waters.