In 1983, the risk of developing severe shock during anaesthesia was estimated to be 1 case in 4600 procedures with an associated mortality rate of 6 per cent. The incidence of severe accidents has further increased since this time. This review focuses on the aspects of anaphylactoid shock (AS) in the context of iatrogenic responsibility involving drugs or substances used during anaesthesia or placed in contact with viscera. The elements predictive of anaphylactoid shock are described together with the arguments involved in a biochemical conception and a physiological conception. The authors emphasize the importance of the operative report and anaesthetic sheet to retrospectively establish the chronology of the events and to facilitate the allergologic work-up. The treatment of AS is an emergency. The therapeutic protocol is relatively well defined and, in addition to IV fluids, adrenalin is the drug of choice during the acute phase of AS. The therapeutic approach to certain particular cases is discussed and future therapeutic concepts are proposed. The aetiological agents of AS are discussed together with their respective frequencies in the specific case of the anaphylaxis reaction. Muscle relaxants are the leading cause of anaphylaxis (70 per cent of cases), especially suxamethonium, vecuronium and atracurium (43 per cent, 33 per cent and 6.8 per cent of cases, respectively). Latex present in various materials, especially surgical gloves, has become the most disturbing substance, responsible for 0.5 per cent of AS in 1989 vs 12.5 per cent of cases in 1991. Hypnotic drugs, although very widely used, are much more rarely incriminated.