In this paper we describe how the open access repositories are valid channels for the publication of scientific grey literature.

Technological development facilitates the communication of scientific knowledge, allowing expand distribution channels and significantly reducing transmission costs of the investigation. There are new paradigms of scientific communication such as open access repositories that must be exploited to provide academic and research free content, so that the scientific production is globally accessible to society.

The aim of this study is to report the benefits of scientific communication model through open access repositories, especially the benefits for scientific grey literature, using as an example the theses deposited in open access and distributed through Gredos, Institutional Repository of the University of Salamanca. We present the fundamentals, the state of the art, trends and benefits of open access, understood as a radical change in the system of scientific communication.

Open Access repositories are a new way to disseminate scientific grey literature so that this literature can achieve maximum dissemination and visibility, increasing the rate of citation.

Currently the movement for open access is sufficiently consolidated. Repositories are a key element in the development of this movement, offering multiple benefits, like visibility and citation, to authors, institutions and the general public. Doctoral theses disseminated through the repositories increase their use, visibility and consequently their rate of citation, while contributing to the public good.