This study aimed to analyze the total oil content in water and sediment and to assess the relationship between the two in the coastal waters of Lalang Village, Medang Deras Subdistrict, Batubara Regency. Samples were collected from three stations representing a tourist area, a river estuary, and an industrial area. The Gravimetri method (API 1340) was used for water, while the Soxhlet method wa…