Evidence-based medicine has brought about a significant change in the role of information and its use on the part of health professionals, who must take appropriate decisions in their daily clinical practice. Evidence-based methodology has encouraged the creation of its own information sources that appraise, synthetise and provide comments on the most pertinent and rigorous current research on a given topic, with the goal of facilitating the decision-making process. The aim of this article is to describe evidence-based medicine's most relevant sources of information, especially those available over the Web that provide reliable answers to clinical questions.