The University of Delaware (UD) is recognized as a center of Problem-Based Learning (PBL) in the U.S.A. Typically, PBL involves three-stage problem solving. Initially, a problem is presented to students, who then discuss along with learning issues, and report the results. The students then discuss the first problem again, and a second problem is presented. The process then proceeds in the same way to a third problem. Good PBL problems are the key to success of PBL. Problems should motivate students to gain a deep understanding, arrive at judgements based on facts and logic, and promote cooperation among students. The First problem should be open-ended and the content objectives should be incorporated into problems. At the UD, ingenious attempts have been made to promote PBL in groups. For example, setting ground rules to prevent “free riders”, specifying the roles of group members, systems for mutual evaluation, peer facilitation, and combinations of group discussion and mini-lectures. The success of PBL at the UD is attributable to a bottom-up approach, sound administrative support and faculty development. The tasks remaining for PBL at the UD include how to cope with the extra load on the faculty, and students feel alienated from PBL.