The aim of this study was to measure polycyclic aromatic hydrocarbons (PAHs) in oysters (Crassostrea sp.) and gastropods (Cymatium sp.) collected from the Can Gio coastal wetland (CGCW), Vietnam. Samples were collected from 14 coastal sites, from both port and non-port sites, during a rainy season (September 2017) and a dry season (April 2018). PAH concentrations in oysters ranged from 3.26 to 64.45ngg–1 wet weight (WW), whereas in gastropods PAH concentrations ranged from 4.81 to 23.80ngg–1 WW. Naphthalene was the major component measured in oysters (0.71–46.74ngg–1 WW), whereas pyrene was the major congener measured in gastropods. Both species showed the same dominant accumulation pattern of two- to three-ring PAH compounds. A temporal and spatial distribution of PAHs in gastropods from the CGCW was also observed: higher PAH concentrations were more frequently observed in oysters and gastropods from port sites during the rainy season. The present study indicates that gastropods Cymatium sp. could be used as bioindicators in tropical coastal areas. Human health risk assessment conducted on the basis of the excess cancer risk suggests that there is no current risk to humans as a result of the consumption of oysters and gastropods.