AbstractVegetable oil methyl esters are increasingly being used as substitutes for petroleum‐based diesel fuels. Because the presence of triglycerides and partial glycerides in the fuel as a result of incomplete transesterification of vegetable oils can lead to serious engine problems, continuous quality control of the product is essential. A rapid gas chromatographic method has been developed for the quantitative determination of mono‐, di‐, and triglycerides in vegetable oil methyl esters.Prior to analysis, mono‐, and diglycerides were silylated withN,O‐bis(trimethylsilyl)trifluoroacetamide; tridecanoin was used as internal standard. Calibration was performed by analysis of standard solutions containing mono‐, di‐, and triolein: the calibration plots for mono‐ and diglycerides showed good linearity, whereas for triglycerides no linearity was observed for triolein concentrations below 0.05 mg/ml. When a non‐linear multi level calibration was employed for the quantitation of triglycerides, the method gave excellent quantitative results for mono‐, di‐, and triglycerides in vegeta