Major bleeding caused by vascular injuries of the abdominal aorta or its branches after blunt trauma often leads to mortality or major morbidity. We report a case that lumbar artery injury following blunt trauma was spontaneously resolved without any surgical or interventional treatment. Lumbar artery injury after blunt trauma could be treated conservatively without surgical or interventional treatment in a selected case. When an aortic or its branch injury was suspicious, diagnostic angiograms in the setting of interventional treatment may be helpful to decide an appropriate treatment modality.