Capillary gas chromatography is nowadays a widely used chromatographic method, used in particular for its excellent resolution. A new alternative method for the hydrogenation of edible oils is being developed. For determining the rate of hydrogenation and the level of isomerisation development during the hydrogenation process capillary gas chromatography has been chosen as the most suitable method for analyses. Fatty acids from partially hydrogenated oils/triglycerides have been converted into methyl esters. By using special capillary columns, Supelco SP 2380 and SP 2560, not only the methyl esters of individual fatty acids, but also the geometrical and positional isomers have been separated.