This is a comparative study focused on the internationalization of teacher education in three countries--Bulgaria, Switzerland, and South Africa. The authors stress on the fact that on the one hand, teacher education is exposed to the increasing imperative to internationalize but on the other hand, teacher education is traditionally to a very large extent nationally shaped. The classical fields of internationalization of teacher education--individual mobility of students and staff, program and provider mobility, internationalization of the curriculum, internationalization of the campus, international cooperation--are used as a basis for constructing the chapter. The authors present these fields in teacher education in Bulgaria, Switzerland, and South Africa. Then, comparing the three different national contexts, some common features, similarities and differences between the countries are analyzed. Finally, the study ends with synthesizing two main challenges that illustrate how an appropriate internationalization of teacher education is still to be developed. [For the complete Volume 15 proceedings, see ED574185.]