A case is reported of successful resuscitation after cardiac arrest due to haemorrhage. Certain aspects of management are discussed, such as the value of aortic compression to conserve blood, when loss is likely to exceed replacement by a substantial margin. The hazards of this procedure and the risks attached to massive blood transfusion are also briefly discussed. Cardiac arrest due to blood loss is, fortunately, a rare event in an operating theatre, but when it occurs the problems faced by the clinical team are formidable and the situation is sometimes regarded as irreversible. A case is presented here in which this accident occurred and in which resuscitation was successful. Some of the problems involved are briefly discussed.