Having concluded its sixth round, PISA is still the most prominent educational study in Germany. PISA attracts special attention since several educational programs and initiatives have been started after the first cycle, which had yielded unsatisfying results. This chapter focuses on professional teacher education as an example of such nationwide measures aiming at improving the quality of teaching and of schools. Two instances for the leverage point “quality of teaching” are presented: (1) the SINUS project initiated to improve teaching and learning in mathematics and science as a program for professional development, and (2) changes in the organization of initial teacher training with the implementation of professional schools of education.