Abstract Pollution by oil and detergent was investigated in sea water of Dardanelles in this work. The highest pollution in surface water was found for oil 232.241 µg/L in Gelibolu and 15.38 µg/L in Kilitbahir and for detergent 62.05 µg/L in Gelibolu, 105.8 11 µg/L in Lapseki and 44.38 µg/L in Kilitbahir. The pollution level was high near seawage point of Çanakkale as 226.27 µg/L for oil and 148.56 µg/L for detergent. The pollution was found higher in 10 m depth than in surface water.