Few studies have examined the perfluoroalkyl substances (PFASs) contamination in less-developed coastal regions. In the present study, we collected 19 riverine and 21 coastal surface water samples in the summer and winter of 2017 to investigate PFASs contamination in the Beibu Gulf, South China. The results show that eleven and twelve target PFASs were detected in the summer and winter, respectively. The total PFASs (ΣPFASs) concentrations in the water of the Beibu Gulf were in the range of 1609-4727 pg/L and 610-4920 pg/L in summer and winter, respectively. Perfluoropentanoic acid (PFPeA), perfluorobutanoic acid (PFBA) and perfluorobutane sulfonate (PFBS) were the predominantly detected PFASs in both seasons with maximum concentrations of 2968 pg/L, 1771 pg/L, and 1764 pg/L, respectively. Strong positive correlations between some PFASs were observed (e.g., PFBA and PFBS, PFOS and PFBS, p < 0.05), suggesting these correlated pollutants may share similar sources. PFASs contamination in the Beibu Gulf was strongly affected by ocean currents, and their concentrations were lower than most coastal waters around the world. Risk assessment indicates a low risk associated with target PFASs to aquatic organisms in the Beibu Gulf. The results of the present research provided a baseline and good overview of the spatial distribution of PFASs along the Beibu Gulf.