Many cases of tardy paraplegia after bony fusion have been reported among well-treated tuberculous spondylitis patients. In most cases, the cause of the paraplegia is known to be spinal cord compression caused by kyphosis, and in these patients cord decompression and kyphotic deformity correction have been commonly performed. A 44 year-old-male patient presenting with thoracic kyphosis and tardy paraplegia was admitted to our department. The cause of his paraplegia was considered to be a compression of the spinal cord by progressive kyphosis. The initial therapeutic plan involved decompression of the spinal cord and surgical correction of kyphotic deformity. However an MRI of the thoracic spine revealed a myelomalacia of the whole thoracic cord associated with severe cord atrophy. Myelomalacia is known to be an irreversible condition with no surgical remedy. Although this condition is very rare, an unnecessary decompressive surgical procedure may be performed if this possiblity is not considered. Because of its rarity and the importance of planning a therapeutic treatment modality, the authors report this case and include a review of the literature.