This book presents a systematic literature review focusing on studies examining teachers' participation in professional development (PD) within Germany, Austria, and Switzerland since 1990. It has identified 81 relevant studies and summarizes the results while answering the following research questions: What are teachers' self-reported reasons participate in formal PD? What barriers do teachers report that prevent them to participate in formal PD? What individual and context characteristics are associated with teachers' PD behavior? Teachers' PD is considered to be an important part of the teaching profession. It is seen as a tool for constant further development for teachers to adapt to changing standards in schools and classrooms, requirements for students, and personal challenges associated with the daily work in school. However, it is repeatedly claimed that there is no sufficient research with regard to teachers' participation in formal PD, as well as of aspects that may influence their PD behavior. In spite of a large number of studies that contribute to this question within Germany, Austria, and Switzerland, only a few of them are cited regularly. Since much of this research is published in German, the results are not accessible for international researchers and comparisons between different countries. This comprehensive review makes these results accessible.