Microplastics (MPs) and plastic-related chemical pollution are widely discussed in the literature. The presence of MPs in environmental compartments create adverse impacts on ecological systems and potential exposure of human through several pathways. Hence monitoring plays an important role in upstream and downstream mitigatory measures. The present study focussed on the capacity building of potential stakeholders for the MPs' monitoring and regulatory measure development. The situational analysis and training need assessment (TNA) of the two countries, Sri Lanka and Vietnam was extensively conducted by using a structured questionnaire, and then information validation was conducted through stakeholder consultations and technical experts (national, regional, and international). Tow working groups consisting of thematic leaders, consultants, and local and international experts were formed for each country for the TNA. The study recognized and proposed, a) education, b) resources and c) institutionalization three main areas for capacity building. The education of the potential stakeholders included a foundation course module on MPs and an advance course module on MPs sampling, analysis, and data reporting for the identified stakeholders in the MPs monitoring chain. The identified area included the selection of sampling locations and sampling methods for water, wastewater, fertilizer, and soil; pre-treatment and transportation samples under the required conditions; selection and development of analytical methods for water, wastewater, fertilizer, and soil samples; identification and quantification of plastic polymer, their state, and potential risk; methods used in data analysis and reporting with minimum information; and use of appropriate data sharing platforms and citizen science data usage.