We report the finding of a probable right atrial thrombus in a 33-yr-old male patient with severe head, chest, and abdominal trauma. Refractory coagulopathy and gross haemodynamic instability ensued, which was only partially controlled with massive blood product transfusion and high-dose inotropic support during laparotomy. Continuous transoesophageal echocardiography revealed a probable atrial thrombus partially occluding the right ventricular inflow tract, which appeared immediately after the patient received 100 microg kg(-1) of recombinant activated factor VII (rFVIIa) via a left internal jugular central line. This is the first report documenting an immediate temporal relationship between rFVIIa administration and a space-occupying lesion compatible with localized thrombosis, despite ongoing severe systemic coagulopathy. We review the clinical use of rFVIIa and discuss possible factors contributing to this event.