The focus of this research project was to examine how problem- based learning (PBL) impacts students' interest and knowledge in computer science (CS) at the elementary level. By focusing on a problem that emphasizes social activism, we hypothesized that PBL CS could increase interest for students. We employed an iterative design-based research approach to examine how the CS PBL curriculum impacted 6th grade students' understanding of and interest in CS, as well as the supports teachers need to implement the curriculum. Results suggest that students' understanding and interest in CS increased. In addition, the teacher reported needing more content PD support, revisions to curriculum to improve comprehension, and other resources.