Regional or systemic air embolism to the heart or cerebrum during endoscopic retrograde cholangio-pancreatography (ERCP) is an increasingly recognized phenomenon. This review aims to give an overview about the current knowledge concerning pathomechanism, diagnosis, treatment, and outcome of air embolism during ERCP. A Medline search was carried out for the key words 'ERCP' in combination with 'liver dysfunction', 'air embolism', 'complication', and 'side-effect'. Altogether 18 reports about 19 patients were found matching with the key words and the topic of interest. Systemic air embolism after ERCP occurred in 14 cases and was associated with cerebral air embolism in eight of them. In six cases with cerebral air embolism the outcome was fatal. Only two patients with cerebral air embolism survived, one of them without a deficit and one with hemiparesis. In only two cases, transgression of air from the venous to the arterial branch occurred through a patent foramen ovale. In none of the patients was transgression attributable to arterio-venous shunts within the lung or other tissues, the Thebesian veins, or insertion of the caval veins directly into the left atrium. In five patients, systemic air embolism occurred in the absence of a foramen ovale. In all these cases it was assumed that air entered the vasculature through the portal or hepatic veins. In conclusion, if patients do not awake after ERCP air embolism should be considered, an acute cerebral and thoracic computed tomography scan should be ordered, and appropriate measures, including aspiration of air from the right ventricle through an acutely floated pulmonary artery catheter or hyperbaric oxygenation initiated.