Background Few studies describe thoracolumbar disc herniation (TLDH) as an isolated category, it is frequently classified as the lower thoracic spine or upper lumbar spine. Thus, less is known about the morphology and aetiology of TLDH compared to lumbar disc herniation (LDH)The aim of study is to investigate sagittal alignment in TLDH, and analyze sagittal profile with radiographic parameters.Methods Data from 70 patients diagnosed with TLDH were retrospectively reviewed. The thoracic-lumbar alignment was depicted by description of curvatures (the apex of lumbar curvature, the apex of thoracic curvature, and inflexion point of the two curvatures) and radiographic parameters from complete standing long-cassette spine radiographs. The rank sum test was utilised to compare radiographic parameters values in each subtype. Results We found two subtypes differentiated by the apex of thoracic kyphotic curves. The apex of the thoracic kyphotic curve located in the middle thoracic spine in type I, and the apex of the thoracic kyphotic curve located in the thoracolumbar region in type II patients. Thirty-six patients were classified as type I, and 34 patients were classified as type II. The mean sagittal vertical axis, T1 pelvic angle and L1 pelvic angle were 27.9±24.8°, 8.2±7.3° and 6.2±4.9°, respectively. There was significant difference (p<0.001) of thoracolumbar angle between type I patients (14.9±7.9°) and type II patients (29.1±13.7°).Conclusions We presented two distinctive sagittal profiles in TLDH patients, and a regional kyphotic deformity with a balanced spine was validated in both subtypes. In view of the different curvatures, different aetiologies were discovered in each subtype. Mismatch between shape and SS value was observed, and better agreement was found in Type II patients.