Summary Hysteroscopy and laparoscopy are essential procedures in the gynaecological diagnostic process, e.g. in the diagnostic workup of infertility. We report a rare case of massive gas embolism with paradoxical embolisation and consecutive cardiogenic shock that occurred during diagnostic laparoscopy. To investigate infertility in a thirty-three year-old woman a diagnostic laparoscopy and hysteroscopy were performed. 105 minutes into the operation a sudden drop in blood pressure occurred necessitating external thorax compression of about ten minutes duration. Since a myocardial infarction was suspected, the patient was transferred to the catheterisation laboratory on high-dose catecholamine. The left ventricular function was found to be markedly depressed with an ejection fraction of only 20% despite normal coronary arteries. Catheter intro­- duction into the left atrium via a patent foramen ovale was readily achieved and an intraaortic balloon pump was inserted. During the following hours the patient needed additional high doses of catecholamines but left ventricular function remained severely depressed. To establish mechanical circulatory support in the event of further deterioration of the haemodynamic situation, the patient was transferred to a heart surgery centre. Over the following hours it proved possible to reduce the catecholamine, and left ventricular function improved. The patient was discharged on day thirteen after the initial event with no signs of neurological impairment. The triggering event had been a massive venous air embolism, leading to increas-ed right heart pressure and paradoxical embolisation of air via a persistently patent foramen ovale resulting in air embolism in the left coronary artery with subsequent myocardial infarction and depressed left ventricular function.