Care for patients is the best way to learn medicine and medical methods and skills. But the availability of real patients for learners is limited. Often the appropriate patient is missed or he can not be demonstrated to all students because of practical or ethical problems. A possible solution is the presentation of a clinical problem by a virtual patient using a simulative computer program. But such an approach means often a lot of work for the author of the case. We developed a flexible and realistic system, CAMPUS (www.medicase.de), which supports the case authors with appropriate vocabularies and a comfortable authoring tool. There are different kinds of case presentations to the users in accordance to the level of professionalism of the user and the scenario the program is used in. An evaluation within an internship has shown, that such pro-grams are judged as useful by medical students. But further studies are necessary to examine if the program will be used for the self-study and to develop further kinds of using scenarios within problem-based curricula.