At the beginning of the 21st century, virtual learning was thought to have the potential to revolutionize learning arrangements. This enthusiastic notion has given way to a kind of disillusionment, which has, however, led to a more realistic assessment of the potential of e-learning, the development of new conceptions, new methodical approaches, and opportunities for cooperation and collaboration. The didactic value of these emerging concepts is now under scrutiny. The project presented in this article included the development, implementation and evaluation of a cross-national blended learning seminar on the didactics of biology. The class included three focus topics dealing with different aspects of biology education. The sample comprised students training to be biology teachers at the University of Technology Dortmund and Hacettepe University in Ankara. All students attended a class called "Teaching Biology" during the winter term 2008/09. The open source e-learning platform Claroline (www.claroline.net) was chosen as the learning environment. Participants had the opportunity to exchange ideas and information, to reflect on the learning process and to complete assignments in international teams. After completing the class, the students evaluated the concept based on their experience. In-class sessions, individual learning, exercises and application ranked higher than online phases, group work, discussions and information exchange. Items evaluating the overall concept received relatively high ratings. Despite the cautious ratings some items received, the positive overall results support efforts to further develop such international teaching concepts. (Contains 6 tables.)