The global carbon credit market has evolved into a key mechanism for mitigating climate change, yet challenges persist regarding transparency, stakeholder trust, and market efficiency. Vietnam is in the early stages of establishing its Carbon Credit Systems (CCS), guided by its commitment to achieving net-zero emissions by 2050. Despite regulatory developments, the Vietnamese carbon market remains fragmented, with concerns over pricing disparities, market liquidity, verification standards, and stakeholder engagement. This study assesses stakeholder preferences in Vietnam’s CCS using an advanced Multi-Criteria Decision-Making (MCDM) approach-based Neutrosophic Sets (NS) integrating Delphi and DEMATEL methods. Unlike traditional fuzzy logic-based models, NS provides a more nuanced representation of uncertainty by incorporating truth, indeterminacy, and falsity, allowing for more accurate stakeholder preference modeling. The NS Delphi method is applied to refine expert consensus, while NS DEMATEL identifies interdependencies among key stakeholder concerns, including policy alignment, financial incentives, verification mechanisms, and market accessibility. Findings reveal that regulatory transparency, price stability, and cross-border certification are critical factors shaping market participation. Moreover, private sector involvement and financial institutions play a pivotal role in market development, requiring stronger incentives and risk mitigation measures. The results contribute to both theoretical advancements in decision science and practical policymaking by offering structured recommendations to enhance Vietnam’s carbon trading system. By integrating stakeholder perspectives with uncertainty modeling, this study provides a strategic foundation for developing a more transparent, efficient, and scalable carbon credit framework in Vietnam, ensuring alignment with global carbon pricing mechanisms and fostering long-term sustainability.