Ankylosing Spondylitis (AS) and brucellosis are two distinct diseases which may be involved both sacroiliac joints and intervertebral discs. Spinal involvement in both diseases may be similar sometimes, and differential diagnosis may be difficult. We reported here a female patient with concomitant AS and brucellosis who was misdiagnosed as spondylodiscitis and sacroiliitis due to brucellosis, because of similar spinal involvement.