This article investigates the continuing professional development (CPD) culture of teachers, and asks how it is influenced by properties of the school system. It reports the results of a questionnaire study with 418 secondary teachers from Sweden and Germany. The results show highly significant differences between Swedish and German teachers' practice of and beliefs in teachers' CPD. This implies a relevant effect of properties of the school system on the teachers' CPD. The differences are explained by varying perceptions of sources of knowledge for CPD, the influence of different school governance instruments, and different historically developed role definitions of teachers in both countries. (Contains 5 figures.)