The ranges of total polybrominated diphenyl ethers (PBDEs) in fish from four Swiss rivers were 0.8–240ng/g in the bile and 16–7400ng/g lipid in the liver. PBDE concentrations varied within each river and among the various rivers. Female fish tended to have higher concentrations in the liver, while the male fish had higher concentrations in the bile. From the resulting PBDE concentrations in fish it could not be infered that these contaminants contribute to the causes of the observed fish catch decline in Swiss rivers.