This document presents the process of extracting lemongrass essential oil (Cymbopogon nardus and Cymbopogon winterianus) in Siem Reap, Cambodia, as a means of diversifying farmers’ incomes through the production of high-value products for the pharmaceutical and cosmetics industries. The production process is standardized into five main stages, including harvesting at optimal maturity, steam distillation, phase separation, and purification, with strict attention to the airtightness of the distillation system and the purity of filtration equipment to preserve the oil’s therapeutic properties and aromatic compounds. Although the extraction yield is relatively low (around 0.16%) and packaging requires advanced technical skills, the model demonstrates promising economic potential, generating an estimated profit of USD 5.64 per kilogram by targeting niche markets that favor natural products. It illustrates how appropriate technology can enhance the value of local agricultural resources while strengthening technical capacity and economic resilience within farming communities.