We present results of a case study in which we analyzed the impact of problem-based learning (PBL) and cognitive scaffolding techniques introduced in our secondary social studies methods course on the perceptions and practices of 12 preservice teachers (PSTs) during their fall practicum and spring student teaching. Our PSTs reported teaching 54 PBL lessons and identified factors that encouraged their use of PBL: methods course PBL experiences; improved student exam scores and writing skills, increased engagement; and improved collaborative, deliberative, and cognitive skills. Discouraging factors included the time and effort to plan PBL lessons, coverage demands, and standardized testing. Findings suggest that PBL methodology, supported by professorial modeling and metacognitive training, had a transformative impact on our PSTs in terms of how they perceived their relationship with their students, the student outcomes they sought to facilitate, and their operational understanding the goals of social studies education offered by the National Council for the Social Studies.