Engagement with socioscientific issues (SSI) is seen as an important citizenship goal of SSI-based science education. In this experimental study, Dutch students (age 8 to 13) participated in lesson series in which they learned about and discussed SSI, such as issues related to the textile industry and wastewater. Attitudes toward SSI indicating engagement were measured among relatively large experimental (n = 236) and control (n = 192) groups prior to and after the intervention. Multilevel analyses showed a positive effect of SSI-based teaching on collective efficacy and no effects on the other seven attitude components. Furthermore, we investigated whether the effects depended on students' SSI-related resources. Students' profiles for use of sources of knowledge (USK) moderated the effect of condition on self-efficacy and--depending on analysis type--on personal relevance, positive feelings, and collective efficacy. The positive impact occurred mainly for students with low USK. We discuss implications thereof for SSI education.