A 25-year-old man with Crohn’s disease presented to the emergency department with sudden onset bilateral leg pain, paraplegia and loss of anal sphincter tone. CT angiography revealed a massive abdominal aortic thrombosis. Revascularisation surgery was performed promptly, saving most of the abdominal organs, but motor function of the legs was not restored. No coagulation disorder was identified, and no other underlying cause for thrombosis was found. It was speculated that it may be related to the patient’s underlying Crohn’s disease.