The authors are reporting 16 cases of ossification of the thoracic ligamentum flavum. Thoracic ossified ligamentum flavum cause myelopathy as a result of pressure on the spinal cord and nerve roots. The prominent symptoms were numbness of the foot or leg, motor weakness, sphincter disturbance and exaggerated tendon reflexes. The male to female ratio was 13:8 and the 5th decade was the most prevalent age group. The predominant regions involved were T9-T10 and T10-T11. Total larminectormy was performed in all patients and the prognosis was good in most cases. The thoracic ossified ligamentum flavum and neurologic disorders due to compression of the thoracic vertebrae by other diseases do not show much of a difference in terms of symptoms. In the past, due to the lack of knowledge of this disease, treatment was performed inapproapriately. However, at the present, with the improvement of CT and MRI and the increased recognition of this disease we believe that good prognosis can be made if appropriate treatment is delivered at the time of diagnosis.