A comprehensive and efficient method is presented for the determination of 9 polybrominated diphenyl ether congeners (PBDEs), 2,4,4' tribromodiphenyl ether (PBDE 28), 2,3',4,4' tetrabromodiphenyl ether (PBDE 47), 2,2',4,4',6 pentabromodiphenyl ether (PBDE 66), 2,2',4,4',5 pentabromodiphenyl ether (PBDE 100), 2,2',3,4,4' pentabromodiphenyl ether (PBDE 99), 2,2',4,4',5,6' hexabromodiphenyl ether (PBDE 85), 2,2',4,4',5,5' hexabromodiphenyl ether (PBDE 154), 2,2',4,4',5,5' hexabromodiphenyl ether (PBDE 153) and 2,2',3,4,4',5,6' heptabromodiphenyl ether (PBDE 183), in mollusc bivalve samples. An experimental design was used to evaluate the influence of several operational parameters on the extraction performance and to obtain the best experimental conditions. Under the final working conditions, freeze dried mollusc was placed in the Soxtec thimble in order to extract PBDEs with 100 mL of n hexane acetone (4 : 1) after 1.5 h and 1 h of boiling and rinsing times, respectively. Soxtec extracts were additionally purified on a multilayered column and after injected in the gas chromatography combined with mass spectrometry (GC-MS) system. Quantitative recoveries of the analytes at three concentration levels ranged between 80 and 108%, and limits of quantification of the method (LOQs) between 0.5 and 20 ng/g. Analysis of mussel and clam samples showed that PBDE 47 and PBDE 99 were presented in almost all samples with concen trations between 0.6 and 2.6 ng/g dry weight. Moreover, a certified reference material (NIST 2974a) was used. The obtained concentrations were in agreement with the certified values.