By reading this article you should be able to: Describe trends in the incidence and agents that cause perioperative anaphylaxis. Explain the underlying pathophysiology. Distinguish the different patterns of clinical presentation and apply the Ring and Messmer severity grading scale. Implement appropriate management for patients with anaphylaxis. Perioperative anaphylaxis is a life-threatening immediate hypersensitivity condition that is usually immunoglobulin E (IgE)-mediated. It occurs rarely, but may lead to morbidity or mortality. The aims of this article are to: i) review the current nomenclature, ii) discuss the key epidemiological points, iii) highlight the key aspects of the underlying pathophysiology, iv) discuss the acute management and therapeutic approach to cardiovascular collapse refractory to adrenaline (epinephrine) and v) discuss briefly the identification of the culprit drug. This article focuses on perioperative anaphylaxis (Grades III and IV) and not the less severe clinical presentations (Grades I and II). We do not discuss perioperative anaphylaxis in children, which appears to be rare. 1 Anaphylaxis in obstetric anaesthesia has been detailed elsewhere.