Kümmell's disease is a rare disorder defined as delayed avascular necrosis of a vertebral body after minor trauma. Diagnosis is based on clinical presentation of delayed onset back pain and kyphosis after minor trauma, and on intravertebral vacuum cleft in radiologic examination. Vertebroplasty or surgical management is necessary to the patients with risks of vertebral collapse or cord compromise, but we experienced a successful result after active conservative management to a patient with severe vertebral collapse and mild spinal cord compression without myelopathy. A 76-year old woman had back pain and gait disturbance 7 weeks after fall down. X-ray and MRI showed a vacuum cleft in T12 vertebra. We treated her conservatively with bed rest and immobilization followed by gradual weight bearing with thoracic-lumbar-sacral orthosis. Back pain and gait disturbance was improved after conservative management, and the improvement was maintained until 8 months after fall down. (J Korean Acad Rehab Med 2007; 31: 776-780)