We present a patient with systemic capillary leak syndrome (SCLS), complicated by obstructive shock due to cardiac tamponade. Methods: SCLS is a rare disease characterised by hypotension, hypoalbuminaemia, haemoconcentration and generalised oedema. Several severe complications have been described, including acute kidney injury, rhabdomyolysis, compartment syndrome and death. We present a patient with SCLS, complicated by rapidly progressive pericardial effusion with cardiac tamponade, for which a lifesaving pericardiocentesis was performed. Because SCLS is often confused with septic shock and anaphylactic shock, an obstructive shock may be easily missed. Although SCLS is a very rare disorder, it is important to be aware of its existence and the possible life-threatening complications, including cardiac tamponade, in order to improve the outcome for the patient. © 2018, Netherlands Society of Intensive Care. All rights reserved.