Metal contamination in seafood may cause adverse effects on human health. The objectives of this study were to determine the concentrations of cadmium and mercury in seafood from the coastal area of Nai Thung sub-district, Nakhon Si Thammarat Province, Thailand, and to evaluate the potential health risk of seafood consumption. A total of 46 samples (including 26 species of fish and shellfish) were caught in March and July 2018. Results indicated that the concentrations of metals in seafood samples were within the standards established for human consumption. However, cadmium concentrations in most shellfish samples were higher than the fish samples, and mercury in fish was higher than other marine organisms. The health risk assessment (HRA) of cadmium and mercury in seafood consumption was between 0.0004 - 0.07 and 0.001 - 0.035, respectively. The results showed that seafood from Nai Thung was unlikely to affect human health.