Concentrations of two types of brominated flame-retardants (BFRs); polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls (PBBs) were determined in a single age class of lake trout (Salvelinus namaycush) collected from the Laurentian Great Lakes in 1997. Mean concentrations of total PBDE were highest in samples from Lake Ontario at 95 +/- 22 ng/g wet weight (ww) or 434 +/- 100 ng/g lipid weight (lw) while the lowest concentrations were observed in Lake Eric lake trout (27 +/- 8.6 ng/g ww, 117 +/- 37 ng/g lw). In all samples, the predominant PBDE congeners were 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), and 2,2',4,4',6-pentabromodiphenyl ether (BDE-100), which are the primary components of the commonly used penta-BDE formulation flame retardant. Lake trout collected from Lake Huron had the highest concentrations of PBBs (3.1 +/- 1.7 ng/g ww, 15 +/- 8.5 ng/g lw), while the lowest levels were detected in fish from Lake Superior (0.25 +/- 0.13 ng/g ww, 1.7 +/- 0.89 ng/g lw). In all lake trout samples, 2,2',4,4',5,5'-hexabromobiphenyl (BB-153), a major constituent of the flame-retardant FireMaster BP-6(R), was the predominant PBB congener. (C) 2002 Elsevier Science Ltd. All rights reserved.