The present article reviews the literature on anaphylactic reactions occurring in the operating room setting. The causes of anaphylaxis are discussed along with the clinical features, treatment and appropriate follow-up for patients who experience this reaction.Anaphylaxis in the operating room can be caused by IgE-mediated reactions, non-IgE-mediated immunologic reactions as well as nonimmunologic reactions. The most common causes are neuromuscular blocking agents and latex, followed by antibiotics and other induction medications. Reactions may present with severe symptoms such as bronchospasm or cardiovascular collapse. Early recognition, followed by the administration of epinephrine, fluids, oxygen and airway control, is the key to a successful outcome. Follow-up testing, through in-vitro and in-vivo methods, is helpful in determining which agent caused the reaction.The management of anaphylaxis in the operating room requires a collaborative effort between anesthesiologists, surgeons and allergists. Protocols for the management of suspected anaphylactic events and subsequent testing should be in place. To prevent future events, patients must receive adequate follow-up and high-risk patients should be identified before they enter the operating room.