Transoral odontoidectomy is a traditional technique to treat congenital basilar invagination (BI) associated with atlantoaxial dislocation (AAD). Although posterior surgery has been a trend to treat most cases, there are still cases that need to be treated through a transoral approach. In addition, intraoperative modern image-guided navigation systems help identify any remnants of the dens and decrease the risk of vertebral artery injury. For symptomatic cases with a history of previous posterior fusion and severe osteoporosis, transoral odontoidectomy is preferred over a posterior-only approach. Our video demonstrates the surgical technique for transoral revision odontoidectomy to treat congenital basilar invagination associated with atlantoaxial dislocation after previous posterior craniovertebral junction surgery. The video can be found here: https://youtu.be/vzcAW8oLcZY.© 2020, The Authors.