The continuous discharge and the presence of the plastic wastes are global environmental issues requiring immediate mitigation and prevention measures to avoid and safeguard the marine biota and human health. Distribution, fate and effects of microplastics on the environment have gained more attention in recent years. The present study aims to synthesize the available data of microplastics to identify the load and trend of abundance in marine environment of South China Sea and the Gulf of Thailand based on mounting evidences on the microplastics reports. The major input of the microplastics to the South China Sea was contributed by Pearl River and the Mekong Rivers of Vietnam and Cambodia. Among the available literature, the Gulf of Thailand found medium plastic abundance level when compared to the other surrounding areas. The outcome of these findings will be an aid in providing the management strategies and decision making in decreasing the entry of microplastics into the South China Sea and Gulf of Thailand which are considered as the most sensitive hotspots in contributing the discharge of plastics into the marine environment. © 2023 Elsevier B.V., All rights reserved.