Negative pressure pulmonary oedema is well described in the literature as an uncommon but recognised complication of general anaesthe sia; negative pressure diffuse alveolar haemorrhage is a rarer consequence. We report a case of massive haemoptysis following elective general anaesthesia using a laryngeal mask airway device and sevoflurane anaesthetic maintenance. The patient had no obvious signs of laryngospasm or other cause of upper airway obstruction perioperatively. We explore the possibility that the haemoptysis was caused by clinically unapparent negative pressure generation, but also ask whether the anaesthetic agent should be considered as a culprit.