To report improvements in post-concussion syndrome and concussion incidence following cervical spinal alignment correction. A 27-year-old professional rugby player with 20 documented concussions presented with abnormal cervical spinal alignment and post-concussion syndrome. After 30 sessions of cervical rehabilitation, health outcomes improved. Post-treatment radiographs showed improved cervical lordosis from -13.5° to -37.4° (ideal is -42°) and right head translation from -22.7 to -11.3 mm (ideal is 0 mm). 2-year follow-up radiographs and 6-year follow-up health outcomes showed post-treatment improvements were maintained. The patient reported two documented concussions in the 6 years following treatment while maintaining the same lifestyle and professional rugby career. Correction of abnormal cervical spinal alignment may help athletes with post-concussion syndrome and reduce risk of concussion. A 27-year-old male professional rugby player with a 6-year history of 20 documented concussions presented with severe neck and headache pain and disability. X-rays of his neck were taken to measure spinal alignment and posture. Also, neck and headache pain, disability and quality-of-life measures were assessed. After 30 treatment sessions of Chiropractic BioPhysics (CBP ) neck spinal alignment and posture rehabilitation, neck and headache pain and disability and quality-of-life improved. X-rays showed improved spinal alignment and posture in his neck. Follow-up x-rays 2 years after treatment showed that the improvements to his neck spinal alignment and posture were maintained. Follow-up assessment 6 years after treatment showed that the post-treatment improvements in in neck and headache pain and disability and quality of life were maintained. Additionally, the patient reported only two documented concussions in the 6 years following treatment maintaining the same lifestyle and competing as a professional rugby player at the same level, position and playing time. This is the first documented improvement in post-concussion syndrome and decreased concussion occurrence following correction of neck spinal alignment and posture. Correction of neck spinal alignment and posture allows the spine to function as a healthy shock absorber and increases its ability to decrease stress transferred to the brain from trauma responsible for concussions and may reduce the risk of concussions. Improvements in post-concussion syndrome neck and headache pain and disability and concussion incidence in a professional rugby player following correction of abnormal spinal alignment and posture using Chiropractic BioPhysics Mirror Image structural spinal rehabilitation.