The mangrove forest of Dumai city house many mollusc species within its narrow habitat. This study focused on the bivalves and Gastropods (molluscs) inhabit the mangrove forest along the coastline. Fourteen species of molluscs were recorded in this survey, eleven of which were gastropoda and three species were bivalves. Species richness and abundance were surveyed at three sites and each site was sampled at ten spots made of 30 spots along the coast. Althogh low in number, Polymesoda expansa and Pharella acutidens were widely distributed across the surveyed sites, while Isognomon ephippium was rare. It was evident from this survey that conservation measures, such as collection quotas need to be established to protect the stocks of those, especially the edible molluscs species in this area. The study also identified two gastropods, Thais lacera and Telescopium telescopium that is known useful pollution bioindicators.