Fish fauna in the upper and middle Ceyhan River basin were investigated with the distribution and systematical determination from May 2001 to April 2004. The fish specimens were obtained by electro fishing and gill nets from two lakes, two reservoirs and 18 streams. A total of 2,414 specimens were collected and 1,156 of these were investigated diagnostic characteristics. Twenty species belong to 10 families were determined. Salaria fluviatilis present stations which under 750 m altitudes while Anguilla anguilla was not present in the upper Ceyhan River basin. S. t. macrostigma was also determined in the streams and river located between 720-1,474 m altitudes. Capoeta angorae, Garra rufa and Alburnus orontis were showed a large distribution in the Ceyhan River system. Gambusia affinis and Clarias gariepinus were determined only in Gavur Lake canals and Kumaşır Lake. Acanthobrama sp. only presented in Sır Reservoir, Silurus glanis and Squalius kottelati presented in Sır lake canals and Menzelet lake reservoir, Cobitis evreni and Aphanius mento were determined in the vegetative areas. Anguilla anguilla bireyleri yukarı Ceyhan havzasında bulunmaz iken Salaria fluviatilis bireyleri 750 m rakımı altındaki istasyonlarda mevcuttur. S. t. macrostigma bireyleri ise 720 ile 1.474 m rakımdaki akarsu ve çaylarda bulunmaktadır. Capoeta angorae, Garra rufa ve Alburnus orontis Ceyhan nehir sisteminde çok geniş bir dağılım göstermiştir. Gambusia affinis ve Clarias gariepinus sadece Gavur Gölü kanalları ve Kumaşır Gölü'nde belirlenmiştir. Acanthobrama sp. sadece Sır Baraj Gölü'nde; Silurus glanis ve Squalius kottelati Sır Baraj gölü kanallarında ve Menzelet Baraj gölünde, Cobitis evreni ve Aphanius mento ise bitikisel floranın olduğu lokalitelerde belirlenmiştir.Anahtar Kelimeler: Ceyhan Nehir havzası, balık faunası, dağılım.