Professional secrecy -maintaining the confidentiality of information received from users or sources --is both a duty for and right of professionals. However, considering the importance of information today, especially since the advent of information and communication technologies (ICT) and the subsequent intensive management of data (personal, public and administrative), it is also necessary to reflect upon this secrecy from the perspective of different informative professions, such as journalists, librarians and archivists. The article attempts to describe, analyze and compare professional secrecy from the perspective of these informative disciplines through an analysis of current legislation. Furthermore, some experiences are presented and differences and similarities are highlighted regarding the exercise of this duty/right in each of these disciplines.