In this study, the levels of pollution in the Ceyhan River (Turkey), subjected to agricultural and industrial pollution, and the effects of these pollutants on the gill and liver tissues, used as biomarkers of Cyprinus carpio were analyzed. Water and fish samples were taken from the polluted region of the Ceyhan River (station II; polluted region) and from the area under the crest of the Aslantaş Dam (station I; control region) located on the same river. The research was carried out during the summer months and 40 fish from each region were studied. The physico-chemical parameters indicated that the water at station II had higher chemical oxygen demand (COD), nitrate, nitrite, pH, and soluble reactive phosphorus (SRP) than at station I. The biomarkers examined in the liver and gill tissues of the carp were superoxide dismutase (SOD), catalase (CAT), glucose-6-phosphate dehydrogenase (G6PD) as well as glutathione (GSH) and lipid peroxidation (LPO). The activities of CAT, G6PD, GST and GSH were observed by the high levels in the liver tissues of the fish in the polluted region. Also, SOD and LPO amounts (P< 0.05 in gill and liver) were also detected as substantially high in the contaminated region.