Harnessing a cluster randomized controlled trial, we estimated the impact on students' advanced placement (AP) examination performance of a project-based learning (PBL) approach to AP compared with a lecture-based AP approach. Through PBL, teachers primarily play a facilitator role, while students work on complex tasks organized around central questions leading to a final product. We estimated positive and significant treatment effects on AP exam performance for the overall sample, within both AP courses studied, and within low- and high-income student groups. Results support teacher-driven adoption of the PBL AP approach within both courses studied, among districts with open-enrollment AP policies and supportive of PBL, for students from low- and high-income households.