Fatty acid profile of high consumption foods by school population of the region Metropolitan of Chile, including trans fatty acid content. The Chilean school population has shown remarkable changes in their eating habits, incorporating high fat content foods to their diet, which could explain the current high obesity rates. A great proportion of these foods uses industrial fats whit high content of saturated fatty acids (SFA) and potentially contains trans fatty acids (TFA) as a result of partial oil hydrogenation or as a natural form in ruminant animals fat. The purpose of this investigation was to determine fatty acid profile, including trans fatty acids, from food consumed by the Metropolitan Region school population. A food consumption survey was applied to 203 Metropolitan Region of Chile school-children, which consisted of questions about food consumption frequency and consumer preferences. Based on the results, ten types of food products were selected. Fat content, fatty acids profile, including trans fatty acid, were determinate by GLC according to the UNE 5509 Norm. Each analysis was carried out in duplicate and three samplings were performed. It was found that a great percentage of the analyzed foods showed low TFA content (<1%). However, some of them presented remarkable saturated fatty acids content, generating a PUFA/SFA ratio with poor fat nutritional quality. The low TFA concentration found in the food may be explained by a decrease in the use of hydrogenated fats, following PAHO/WHO recommendation, which are being applied in Chile.