Commercialization of new technologies may be hampered by stakeholder resistance and a sceptical public. Genetic modification (GM) has suffered particularly from such problems. At present, for example, practically no products exist on the shelves of European retailers that are labelled as containing GM organisms or their derivatives. In the absence of product experience, consumers tend to evaluate this technology by means of affective mechanisms, setting it in relation to other, even more abstract and general socio-political attitudes. Previous research has shown that these attitudes are resistant to all forms of communicative interventions. A study is presented in which the effectiveness and mechanisms of direct-experience interventions are experimentally tested. Results indicate that the positive affect evoked by a single trial of a high-quality genetically modified food can lead to strong changes in consumer attitudes (effect size d = .40). Furthermore, preferences for genetically modified products were found to be mainly dependent on the quality of the product participants had tried. Both effects were robust under contextual variations. Results are discussed in terms of theory and practice, focusing on point-of-sale promotions that could be the key element in the launch of the first genetically modified foods in markets that are as yet GM-free.