A method is proposed for determining the mass of oil pollution per unit area of bottom sediments of water bodies, which makes it possible to associate pollution not only with the concentration of pollutants, but also with the area of the reservoir. The approach relates to the field of environmental protection, in particular to the analytical control of the content of oil pollution in mineral, organogenic and mixed bottom sediments. It can be used for environmental monitoring of polluted water bodies, for assessing the damage caused to a water body, and for planning treatment works. The method for determining the mass of oil pollution per unit area of bottom sediments of water bodies includes sampling, drying the sample to an air-dry state, extraction of oil products from bottom sediments, chromatographic separation of oil products from associated organic compounds of other classes, quantitative determination of oil products by absorption intensity in the infrared spectrum. A survey of 88 oil-contaminated reservoirs within the Samotlor oil field in the north of Russia was carried out, in which the proposed method was tested.