Plastic waste pollution poses a critical challenge for environmental sustainability and socioeconomic well-being and is a severe environmental problem that has a significant impact not only on the natural ecosystem but also on socio-economic issues. To solve problems related to plastic waste pollution, we must clearly understand the current situation and related issues arising from plastic pollution in the research area. In this study, plastic input and leakage were examined during pre- and post-monsoon periods in the coastal regions of Can Gio District. Fifty-seven transects with differing ambient population densities in the study area were investigated for litter leakage, along with evaluations of single-use plastic consumer goods at the point of sale. The results showed that population density and pre- and post-monsoon periods did not affect litter densities. The CEI values representing 75% of the study area were classified as “clean,” and the litter density values representing 75% of the survey area were below 0.16 items/100 m. Most single-use plastic consumer items are produced domestically, facilitating the implementation of extended producer responsibility regulations.