This study examined whether participation in a role play on the socio-scientific issue of the use of nuclear power had an impact on pre-service primary teachers’ ideas regarding the process of obtaining electricity in a nuclear power station. Before and after the role play, 78 pre-service primary teachers were asked to describe this process to analyze the ideas they displayed about the stages involved in it. The results showed, overall, an increased presence of more scientifically informed ideas in some of these stages following the role play, although a number of nonscientifically informed ideas persisted, for example, regarding the way in which heat is obtained or the final transformation of energy into electricity. These results support the potential value of role play for developing more scientifically informed ideas, although some modifications of the role play are recommended for further development of them.