Trigeminal trophic syndrome is an unusual cause of facial ulcers that affects the sensitive area of the trigeminal nerve. Trigeminal trophic syndrome (TTS) is an unusual condition characterized by anesthesia, paraesthesias and ala nasi ulceration, following peripheral or central damage to the trigeminal nerve. We reported a 27-year-old man who presented with a left ala nasi ulcer accompanied by pruritus and paraesthesia for two months and one month before admission, he was a case of car accident that was admitted in ICU due to diffuse axonal injury (DAI). An underlying infectious, malignant and vasculitic cause for the ulcer was excluded by a skin biopsy. So awareness of the predisposing factors and clinical presentations of this important disfiguring condition seems to be necessary to ensure prompt diagnosis and treatment.