Priorities in the diagnosis and treatment of a multiple trauma with injuries to the thorax and pelvis are usually determined by the pattern and the severity of the injury sustained. In this case a haemodynamically unstable patient with severest pelvic trauma and a moderate thoracic trauma developed progressive haemodynamic instability during an intervention to the pelvis, resulting in a lethal outcome for the patient. The cause only became obvious when computed tomography of the thorax (CTT) was performed which was able to demonstrate venous pulmonary bleeding compressing the left atrium. In haemodynamically unstable patients with a major pelvic trauma combined with a moderate thoracic trauma, early CTT should therefore be a main priority in the initial management of such patients in the resuscitation room. The time spent on such a diagnostic procedure seems to be worth the information gained, which can significantly influence the initial choices and priorities in treatment.