Substance use prevention programming for youths in the United States has typically followed evidence-based methodologies that have been subjected to rigorous evaluation and review. Modifying such programming to suit local cultural norms requires that researchers provide schools and teachers with specific information on how to modify the programming. Yet, such modifications prove difficult because more often than not programming has been broken down into themes, each one of which would require modifications. Moreover, in the United States, there is a tendency to regarding the administration of the recommended substance use prevention “packages” as sufficient to meeting the school substance use prevention task. On the other hand, in Nordic countries the most popular form of school prevention work is informal and involves the daily conversations between students and teachers. Yet, there has been a move toward more formalized “prevention work” in Nordic schools that relates to a specific planned project or program implementation. However, Nordic countries consider the teachers and not the researchers as the legitimate decisionmakers in schools. Researchers are regarded as people who might support the development of an educational program regarding substance use prevention. The consequences of these differences is that the empirically-driven, controlled experiments used to evaluate school-based programming in the United States is inappropriate for evaluating the more informal prevention programming that takes place in Nordic schools. The authors hope that this analysis will spur research on the development of the necessary evaluation methodologies required by Nordic countries that administer school-based prevention programming. Glossary, notes, references