Problem-Based Learning (PBL) can be defined as a learning environment where problems drive the learning. A teaching session begins with a problem to be solved, in such a way that students need to gain new knowledge before they can solve the problem. This paper discusses the application of PBL to teaching an introductory course in engineering mechanics at Aalborg University, Copenhagen, Denmark for first semester students enrolled in the program “Sustainable Design". We pose realistic problems which do not necessarily have a single correct solution. Project work in groups also presents itself as a supplement for conventional engineering education. The students themselves should interpret the problem posed, gather needed information, identify possible solutions, evaluate options and present conclusions. The paper also presents an initial assessment of the experiences gained from implementing PBL in the course. We conclude with a discussion of some issues in implementing PBL in engineering and mathematics courses.