The milk consumption in Chile has persisted between 124 and 134 Ls per capita since 1996, numbers that are below the recommendations of national and international health organizations, in spite of the promotion instances of its consumption created by public and private institutions of the country. In order to characterize the decision-making process in milk consumer’s purchase in supermarkets in Temuco, Araucania Region of Chile, and to determine the relevance of the brand as attribute of selection, a survey to 400 persons was made. Considering the answers of the survey, 92,7% declare to be milk consumers. It was found that the family group carried out milk consumption daily. Supermarket’s offer, family and personal preferences mainly influenced the purchase decision. And this process takes less than four minutes. This decision was based on the milk flavor, fat content and the price. The preference over a particular a brand was mainly based on the trust it generated on the consumer. Women made the purchase decision and bought the milk. 45,6% showed to consume fluid milk, 25,1% powder milk, and 29,4% both of them. There was a high degree of conformity in the product bought after its consumption; the common answer on the contrary case corresponded to a change of brand. Using conjoint analysis, it was determined that the brand had a 55,2% of relative relevance in the decision-making process, compared to the packaging and the price.