A contextual approach to the phenomenon of false news in the field of information and documentation is presented, taking into account the role that professionals in the sector can exercise efficiently. We present a description of projects, both from library institutions and their professionals, and from the education and communication sectors, also affected and involved in the problem of fake news and post-truth. In the conclusions the required revision of a series of practices and activities so far developed is stated, with both the participation and the collaboration with other professional sectors involved, and the implementation of training projects in digital and media literacy. © 2018, El Profesional de la Informacion. All rights reserved.