Engineers Without Borders USA (EWB) is a nonprofit organization that partners student chapters with communities in fundamental need of potable water, clean air, sanitation, irrigation, energy, basic structures for schools and clinics, roads and bridges, etc. While EWB projects may vary in complexity, they are all realistic, ill-structured and challenging, and so have the potential to provide a unique educational opportunity for problem based learning (PBL). Since the number of EWB student chapters on college campuses is large and growing, this paper explores whether EWB is well aligned with PBL, and the extent to which participation in EWB increased student learning in a cohort of engineering students at the City College of New York. Student learning is assessed for various technical and non-technical learning outcomes (i.e., ABET program outcomes). EWB is found to be well aligned with the PBL approach. For the student cohort studied, participation in EWB appears to reinforce technical concepts learned in the classroom and to provide a forum for developing an appreciation for or ability in particular concepts that are difficult to adequately address in a classroom setting: ethical behavior, global perspectives, sustainable solutions, effective communication, decision-making and leadership.