Professional development of the members of any organization is a key and essential factor to promote innovation and, ultimately, the improvement of public organizations. Communities of practice is one of the leading strategies used to promote knowledge management processes aimed at generating organizational and individual and informal learning. This chapter presents some of the results and proposals from an extensive study developed in two phases which focus on some key factors for promoting innovation in public administration. The first phase tries to identify some of the mechanisms that facilitate or hinder learning, organizational and informal, in public organizations. The second phase is focused on analysis of knowledge management practices through communities of practice in public administration. The results enable us to suggest some proposals and future research lines aimed at improving both organizational and informal learning, along with innovations that contribute to improving the public administration.