Trans fatty acid content in food products might have impacts to human health. The labelling policy particularly on trans fatty acid (TFA) on food products has created a demand on a quick method that can be used to determine trans fatty acid low content in food products. The testing method used in this research is from International Olive Oil Council (IOOC) to determine TFA<1% in vegetable oil. In order to see the performance of the method used in the testing, a validation of the method is conducted. The result from method validation showed that detection limit values was 0.05% and % recovery of the certified reference material BCR 162 used as matrixes was within the range of 68-106%, meanwhile % precision was within the range of 0.1%-13.7%. Hence, the validation of IOOC method on cis and trans fatty acids of vegetable oil determination using chromatography gas (TCR-CN100 60 m x 0.25 mm x 0.2 μm) with FID detector showed that the testing method can be used to determine cis and fatty acids<1% in oils/fats. This method has been applied in the testing some commercial vegetable oils available in the market (palm, sunflower, soybean, coconut, and corn oils). The results were not significantly different from the reference standard.