Abstract The oil pollution was carried out at 8 stations in eastern part of the Izmit Gulf. Oil contamination was determined by using the Iranian crude oil, imported mostly by TÜPRAS, Izmit Refinery, as the reference material. Oil levels found in this area varied in 2002 as 4.81-144.37 (µg/L), in 2003 1.52-9011.3(µg/L). When these findings are compared with the earlier results of 1994-1995 periods, and after the Gölcük – Izmit earthquake of 17 August 1999, the conclusion so reached has indicated that the rate of pollution decreased during the years. Outcomes for the Naval Zone Gölcük has been more promising and revealed that the rate of pollution sharply decreased as compared with the 1994-1995 results.