<p>Molluscs, being highly susceptible to potentially toxic elements (PTEs) and easily accessible for human consumption, play a critical role in research on PTE pollution. This study focuses on Kukup Fishing Village in Johor, Malaysia, to investigate the levels of Cd, Cu, and Pb in seawater, sediment, and the soft tissues and shells of the gastropods <i>Nerita articulata</i> (lined nerite snail) and <i>Cerithidea obtusa</i> (obtuse horn shell). All collected samples were chemically digested before being analysed using the flame atomic absorption spectrometer (F-AAS). It is found that the PTEs are mostly accumulated in soft tissues and shells, followed by sediments and seawater, respectively. Besides, the results revealed that all study locations exhibited moderate to severe pollution, and the PTE concentrations in sea snails exceeded the thresholds set by the Malaysian Food Regulations (1985). The mean concentrations of the studied elements in the seawater, soft tissues, and shells of two studied species were found to be in the order of Pb &gt; Cu &gt; Cd. Additionally, Pb was heavily accumulated in the soft tissues of both species: <i>N. articulata</i> (712.587–723.242&#xa0;ppm) and <i>C. obtusa</i> (705.935–708.626&#xa0;ppm). Compared to <i>N. articulata</i>, <i>C. obtusa</i> showed a higher capacity to accumulate Cd (3.702–4.350&#xa0;ppm) and Cu (92.687–157.445&#xa0;ppm), particularly in the soft tissues. The shell of <i>N. articulata</i> and the soft tissue of <i>C. obtusa</i> were identified as potential biomonitoring indicators for Cd and Cu, respectively. It is recommended that the local Malaysian authorities could strengthen environmental management, implement regular monitoring, and raise public awareness to minimise seafood consumption from polluted areas as these measures could aid to reduce pollution, protect marine ecosystems, and safeguard public health.</p> Graphical Abstract <p></p>