Ankylosing spondylitis is a chronic and progressive inflammatory disease involving the sacroiliac joints with HLA-B27 positivity in 85 % of the patients and radiologically evidence of sacroiliitis. It is associated with several extraarticular manifestations, but neurological complications are rare. Occurrence of multiple sclerosis in patients with ankylosing spondylitis has been reported in limited cases. Adalimumab, a TNF-alpha antagonist, offers a significant improvement in ankylosing spondylitis and is considered to be less immunogenic and more tolerable than other TNF-alpha blockers. A case of multiple sclerosis coexisted with HLA-B27 positive ankylosing spondylitis after treated with adalimumab was reported.