Water, sediment, various tissues of fish, crustacean, gastropod and bivalve were collected from major river basins in Vietnam and, analyzed for the presence of perfluorinated alkyl substances (PFASs). Furthermore, the occurrence of PFASs in coastal, tap and well waters collected from eight different regions in Vietnam was investigated. PFOA and PFOS were consistently detected as the dominant PFASs in surface waters. The greatest concentrations of PFOA (53.5 ng L-1) and PFOS (40.2 ng L-1) were found in a surface water sample collected from a channel that receives wastewater treatment plant discharges. PFOS and PFHxS were found as the predominant PFASs in sediments. The greatest PFAS concentration in biota was 16.9 ng PFUnDA g(-1) wet weight found in a fish liver. Some long-chain PFCAs including PFNA, PFUnDA and PFTrDA as well as PFHxS were more abundant than short-chain PFASs in biota tissues. The measured concentrations of PFOS and PFOA in surface and tap waters were below the provisional health advisory. The rank order of mean bioconcentration factor of PFOS in biota was; crustacean (115 L/kg), gastropod (1117 L/kg), fish (1120 L/kg) and bivalve (2110 L/kg). This study provides baseline information for a better understanding of PFASs contamination in Vietnam. (C) 2016 Elsevier B.V. All rights reserved.