Introduction Intracranial hypotension (IH) occurs typically spontaneous and is a potentially life-threatening condition characterized by symptoms varying from postural headache to coma, with classical magnetic resonance imaging (MRI) findings. Case description We report two cases of clinically relevant trauma-related IH and review of the literature. One patient with a cerebral trauma presented unilateral mydriasis and coma resolved by the Trendelenburg position (-20°) as urgency intervention. In the second patient, IH was caused by a lesion of the brachial plexus after a motor vehicle accident. Discussion and conclusion A history of mild or moderate trauma in association with prolonged postural or permanent headache may indicate IH. Posttraumatic IH is rare, nevertheless life-threatening in case of misdiagnosis. Intracranial hypotension in a trauma context is rarely described and difficult to diagnose. The change from tipical supine 30° to Trendelenburg position (0–20°) can be a life-saving manoeuver in these patients