We investigated how teachers' attitudes on GMO in 30 countries relate to two Major Environmental values of Preservation and Utilization. Participating teachers (N = 10651) filled in a questionnaire including items on Preservation-and Utilization-related values (Major Environmental Values, 2-MEV model), and on attitudes to GMO. We analyzed the responses using Exploratory Factor Analysis, and investigated the structure of attitudes based on the multivariate structure. The study confirmed the bi-dimensional nature of the 2-MEV model. The GMO items formed an independent third dimension, although several Pro-GMO attitudes were related to Utilization values. We also found variation of attitudes among countries, plausibly reflecting the influence of different socioeconomic and cultural contexts. The results indicate that attitudes and reasoning on sensitive socio-scientific issues such as GMO relate partly to the basic Environmental values of Preservation and Utilization, and partly to pro or anti-GMO attitudes. 2