Posttraumatic carotid-cavernous fistula (PtCCF) is an uncommon complication after cranioencephalic trauma. It is usually diagnosed with a cerebral arteriography when the clinical symptoms have already appeared. The transcranial color-coded duplex sonography (TCDS) is a non-invasive technique at the patient's bedside that permits visualization of the circle of Willis and the intracavernous segment of the internal carotid artery. The initial sonographic patterns that suggest the presence of a PtCCF by TCDS are a mosaic image in color mode, presence of arterial and venous flows mixed with high velocity and low resistances. We present our experience in the early and non-invasive diagnosis of PtCFF in an Intensive Care Unit.