Protecting wetlands from environmental pollution has been of significant importance, as they are the vital habitats for various kinds of birds and animals. This study has aimed to monitor the contamination of Cd and Pb in Anzali wetland, located in the north of Iran using a mussel biomonitor. The contents of Cd and Pb were measured in the surface sediment, the soft tissue, and the shell of A. cygnea. The samples were collected from four sites in the region. The results demonstrated that the shell of A. cygnea can be employed as a precise case for biomonitoring of Cd and Pb, due to the higher biota-sediment accumulation factor and the lower coefficient of variation values found in the shell compared with the soft tissue, and also according to the positive correlation between Cd and Pb levels in the shell of A. cygnea and the sediment.