Genetically modified transgenic foods (TF) have generated considerable debate in developed countries. Therefore, a survey of 400 people was conducted to assess the importance of this variable in consumer decisions regarding the purchase of liquid milk and tomato sauce in Temuco (IXth Region, Chile). This survey also evaluated the existence of different market segments. Using a conjoint analysis, we established that the presence of genetic modification (GM) in food was a more important factor than either the brand or the price in both types of food. Using a cluster analysis, five consumer groups were distinguished, with two large groups representing 46.8% and 18.8% of the total number of people surveyed. These two groups felt the existence of GMs to be important, but only the largest group preferred the alternatives with no GMs. For the third group (16.8%), brand was the most important attribute, but a preference for non-TF was also shown. The fourth group (10.5%) placed great importance on price and preferred non-TE The smallest group (7.3%) placed a slightly higher value on the price of milk and on the brand of tomato sauce, showing a preference for TF The five groups all rejected the store-brand product and most consumers reacted positively to lower prices. Therefore, with the results of this investigation, it can be concluded that the absence of GMs in milk and tomato sauce is a desirable condition for a large proportion of consumers in Temuco (74%), but there are groups of consumers (26%) that accept genetic manipulation of these foods.