Background: There has been considerable enthusiasm among scientists and industry about the possibilities of biotechnology and especially genetically modified organisms (GMO) in food production. At the same time, there has been considerable scepticism by consumers, much public debate, and a cautious approach from retailers. On this background, a study was designed to answer four questions: 1. How negative are consumer attitudes to GMO applications in food? 2. How much do these attitudes affect product evaluation and purchase behaviour? 3. How deeply rooted are these attitudes? 4. Can the attitudes be changed by more information? The study: The study on which the present paper draws investigated consumers in Denmark, Germany, Italy and the UK. A multi-method approach was employed combining qualitative laddering interviews, nation-wide surveys, and experiments. In the product-specific parts, a yoghurt produced using a GMO starter culture and a beer brewed using GMO yeast were used as examples.