This article reports from a 1,5 yearlong co-design process where mainly one researcher and four science centre educators collaboratively designed a controversy-based educational programme for upper secondary school in a Norwegian science centre. Its aim was to contribute to our understanding of the transition in science centres from embracing neutral, science facts, to invite visitors to discuss and think critically about contemporary issues. The data for this study consists of sound recordings from one group interview, eight workshops and three informal meetings. In the analysis, we identified barriers related to both choosing a controversial issue and choosing pedagogical activities. For example, to address an issue that was both science and society based, and finding ways to engage students in discussion. Based on our findings, we recommend paying special attention to the role of sparking students’ emotional engagement, the aspect of no right or wrong answer, and the balance between hands-on activity and dialogue when designing controversy-based activities in these institutions.