Paradoxical embolus, the passage of an embolus from the right to the left side of the circulation, was formerly recognised as a postmortem diagnosis. More recently, survivors with paradoxical embolus have been described. A case of paradoxical embolus is described in which the diagnosis was made clinically, and an imminent further embolus visualised by transoesophageal echocardiography, which was successfully treated surgically. Treatment strategies are discussed.