In this paper, we report our experiences on teaching the Unifi ed Modeling Language in the large. More precisely, about 1000 computer science and business informatics students attend our course Object-Oriented Modeling each year. Requiring a profound understanding of the UML, many advanced courses like Software Engineering or Model Engineering build on the knowledge imparted by our course. In order to achieve our ambitious teaching targets, we establish personal mentoring despite the mass enhanced with e-learning facilities.