Postoperative complications are major healthcare problems and are associated with a reduced short-term and long-term survival after surgery. Major surgery is associated with a predictable and usually transient Systemic Inflammatory Response (SIRS), depending on the magnitude of the surgical trauma. An excessive SIRS syndrome participates to the development of postoperative organ dysfunction, infection and mortality. Corticosteroids may decrease the postsurgical SIRS in cardiac surgery: in a large multicenter randomized trial, a single intravenous administration of high-dose dexamethasone did not reduce the incidence of a composite endpoint of adverse events but was associated with a reduced incidence of postoperative pulmonary complications and infections and with a reduction in hospital stay. However, a similar study, recently published in the Lancet was negative. Evidences from one meta-analysis, including 11 studies of moderate quality (439 patients in total), suggest that intraoperative administration of corticosteroids during major abdominal surgery decreases postoperative complications, including infectious complications, without significant risk of anastomotic leakage. At present, no large randomized controlled trial has been performed in patients undergoing major non-cardiac surgery. In acute medicine, several lines of evidence have shown that low to moderate doses of corticosteroids decrease the excessive inflammatory response, without inducing immuno suppression. However, despite the widespread use of corticosteroids to reduce postoperative nausea and vomiting and to improve analgesia, concerns continue to be raised about their safety, especially regarding an increased risk of postoperative infection.