The aim of the study has been to describe, analyse and discuss the latest research findings on the professional development that is accomplished through collective and cooperative processes among teachers. The research question addressed in this article is: "In which ways do professional development and learning occur in schools, and which improvements may be identified in the practices of teachers related to professional development and learning?". The theoretical framework for the research is cultural historical activity theory (CHAT). In the CHAT perspective, knowledge is perceived as constructions of meaning and understanding within social interaction. The social interactions and surroundings are seen as decisive for teachers' (in this case) learning and development. The main argument is that teachers' professional development can lead to improvements in teachers' teaching and development of teachers' pedagogical thinking about students learning and development. To answer the research question, a search was carried out in the field of pedagogy in ERIC (Education Resources Information Center) (performed on 4 January 2018). The search strings "teacher professional development", "teacher learning" and "professional development" were used and restricted to the time period from 2015 to 2017. This study finds that many factors impact and influence the professional development of teachers. Collective processes in professional learning communities (PLCs) in an environment dominated by trust between the participants are important. Findings moreover show the importance of teachers having influence on planning and initiation of teachers' professional development. The study also shows that external support has an impact on teachers' professional development.