The research analyses the cost structure of stakeholders and marketing channels efficiency of Num mango in Vietnam. By employing this approach, stakeholders can recognize potential risks and proactively create marketing channels and profit scenarios to minimize those risks. This enables them to develop sustainable business strategies that promote long-term success and contentment. The study applied a global value chain approach to analyze the cost structure and marketing efficiency of stakeholders. Total sampling observation was collected 317, comprising 228 farmer households, 20 collectors, 15 wholesalers, 30 retailers, 6 companies, 8 supermarkets/fruit shops, and 10 supporters (5 transporters, 3 agro-input dealers, 1 central market, and 1 agency of phytosanitary inspection 2 for import and export). The study shows that the Num-mango value chain contains 5 market channels, 2 export channels, and 3 domestic channels. In general, there is a variation in the production cost of Num mango across different marketing channels. This discrepancy primarily arises from the distinct criteria and quality standards set by each market channel. Consequently, the cost of producing Num mango differs depending on the specific market channel. Farmers are the vulnerable link in the whole mango value chain. The Num-mango growers are recommended in case 2 (market channels 1, 3, and 5). In this case, farmers must consider carefully channel 1 and 3 marketing expenses. Marketing cost management boosts 1 and 3 channels' efficiency and farmer earnings. This improves marketing channel efficiency and increases mango value chain sustainability.