Inflammation is a major component in keeping the body in homeostasis. However, an overwhelmed inflammatory response may be associated to a loss of this homeostatic status, which may lead to tissue injury or organ dysfunction. A huge number of drugs interacts with the inflammatory response in a positive, negative or "dual" manner. Among these drugs, ketamine seems to have a significant positive effect on the regulation of inflammation. This NMDA-receptor antagonist acts at different levels of inflammation, interacting with inflammatory cells recrutment, cytokins production, and inflammatory mediators regulation. The resultant effect of these interactions confers to ketamine a anti-proinflammatory effect by limiting exacerbation of systemic inflammation without affecting local healing processes. This review makes a complete overview of the immunomodulatory properties of this complex anesthetic substance.