The paper analyzes the welfare effects of the introduction of GMO technology into a market in which a fraction of consumers refuses to buy GMOs. Our theoretical model recognizes that segregation and identity preservation (IP) of non-GMOs may create costs for both IP producers and non-IP producers. Our results show how GMO-hating consumers may win or lose from the introduction of GMO technology. If IP creates costs for non-IP producers, indifferent consumers and GMO producers may be made worse off because others refuse to consume GMOs. If GMO rejection is strong, IP producers win when GMOs are introduced, even though they do not produce GMOs.