The current study is about students' engagement with socioscientific issues (SSI). We explored the use of sources of knowledge about SSI and attitudes toward SSI among a sample of 1676 Dutch 8- to 16-year-old students. First, we developed a questionnaire that measured students' use of four sources of knowledge about SSI: Social Resources (online media use and talking with parents and friends), In-Class Resources (in-class talk and in-class offline media use), Visit Resources (visiting the zoo or a science museum with parents or school), and Offline Media Resources (engaging with issues or the news via books, magazines, newspapers, or TV). Second, we performed a latent profile analysis to explore students' patterns of use of these sources. This resulted in five profiles: Social Visitors (5.9%), Offline Media Consumers (10.6%), Media Discussers (14.3%), In-Class Users (21.0%), and Non-Users (48.3%). Third, we related these profiles to students' attitudes toward SSI, as measured with the Pupils' Attitudes toward Socioscientific Issues (PASSI) questionnaire. In line with the sources of knowledge profiles, the Non-Users felt and thought most negatively about engagement with SSI, while the Media Discussers showed the most positive attitudes. We believe that our exploration of the profiles adds to the discourse about students' socioscientific capital. Moreover, this study informs teachers about the resources that students may bring into the learning environment and their decision-making about SSI. The study concludes with practical suggestions about stimulating the use of sources of knowledge for certain groups of students and fostering positive attitudes toward engagement with SSI.