The target of the present study is to develop the methodology for determining polybrominated diphenyl ethers (PBDEs) in fish and fish products for the control of impurities content in foodstuff and environmental objects in general. We analyzed chromatography conditions (temperature conditions, effect of speed and split ratio of the gas-carrier flow using HP-1 capillary columns, and the extract purification methods, lipids-destructive and non-destructive, at determination of PBDEs. We suggested the method for determining 2,2,4,2,2,4,4, and decabromodiphenyl ether Introduction. The particular attention being actually paid to polybrominated diphenyl ethers (PBDEs) is due to their wide industrial application as flame retardants, resistance to environment, bioaccumulative potential, high toxicity and carcinogenic effect to humans.Polybrominated diphenyl ethers are a class of dicyclic aromatic ethers where the hydrogen atoms of the first and second benzene rings are substituted by bromine atoms. Bromine atoms per molecule are: n + m = 2 ¸ 10 (Figure 1). There are 209 congeners of PBDEs. Depending on the number of bromine atoms per molecule, there are 10 PBDEs homology groups classified: mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-and decabromobiphenyls. The said homology groups are 3, 12, 24, 42, 46, 42, 24, 12, 3 and 1 isomers,