The coastal and marine environment are currently polluted by microplastics (MPs) worldwide. Transfer of MPs from land to sea and their inclusion in the food web has a significant adverse effect on the marine life and human health. The aim of this study was to quantify microplastics in soft tissue of green musselPerna viridis (Linnaeus, 1758) sold in Nahkon Pathom and Salaya fresh market, Nakhon Pathom Province, Thailand. The total number of MPs was 30 items in mussels from Nahkon Pathom fresh market and 23 items from Salaya fresh market.The average content of microplastics was 0.51 ± 0.22 items/g (wet weight) in mussel sold in Nakhon Pathom fresh market, whereas in mussel sold in Salaya fresh market was 0.30±0.22items/g (wet weight). Over half of the microplastics were 250-500 µm in size, and the most common shape was fibres (66%) and fragments (34%). The dominant color was blue (62%) and violet (38%). Polymer types were identified usingFT-IR microscope, and the major component was polyethylene terephthalate (PET),polyvinyl alcohol (PVA) andpolypropylene glycol methacrylate (PGM).Microplastic contamination was found in each soft tissue of green mussel individual. The findings indicated that the microplastic content of bivalve soft tissue was transferred to humans when they consumed whole soft tissue.