This chapter focuses on computational thinking, which is widely recognized as one of the essential twenty-first century skills. Computer science teachers should be familiar with computational thinking and build their own conception of its essence and central ideas for two main reasons: First, computational thinking is connected to computerized processes (but not only) expressed by algorithmic thinking; second, computer science teachers have a unique role in the implementation of computational thinking in educational systems and the promotion of its conceptualization. This chapter presents several common educational approaches to computational thinking, analysis of the relationships between computer science and computational thinking, recommended pedagogical principles to be implemented in computer science teacher preparation programs in general and specifically, in the MTCS course, and activities to be facilitated in the MTCS course and computer science teachers’ professional development programs.