Considering the high level of concern caused by genetically modified foods (GMF) in developed countries, the relevance of this variable in decision-making about the purchase of fluid milk among consumers in Temuco (La Araucanía Region, Chile) was determined. By means of a personal survey of 400 people and using conjoint analysis, it was determined that the presence of genetic modifications in food was more important (44.7%) than brand (29.5%) and price (25.5%) in the decision-making process. By cluster analysis three segments were identified; the largest group (46.5%) gave similar relevance to food production and brand, preferring genetically modified milk. For the second group (41.5%), the presence or absence of genetic modification was the most important variable in the purchase, with a strong rejection of milk produced by genetic manipulation and preference for non-transgenic milk. The minority segment (12.0%) placed a higher value on price. These three segments prefer national brand milk, reject the product with private brands and react positively to lower prices. The most sensitive segment to genetic food manipulation had a higher proportion of people under 35 years of age and with no children. It is concluded that the absence of genetic manipulation in food is a desirable condition, mainly for young consumers of La Araucanía Region.