Ankylosing spondylitis is an arthritis which involves the bones of the spine and can cause pain and stiffness of the back. It generally involves young men. However in some rare situations it can lead to a complication called anderson lesion. The same can appear similar to tuberculosis. The treatment of arthritis and tuberculosis are very different and hence correctly identifying the correct problem is very important. Dr. Karthik Urala H A and Dr. Shiva Prasad B N from Mysuru, Karnataka presented a report of a patient in the Indian rheumatology conference in Guwahati. A 45 year old man with Ankylosing Spondylosis(AS) for 15 years on treatment with NSAID’s and Sulfasalazine presented with severe pain over mid back region of 1 month duration. MRI spine showed the complication non-infective spondylo-discitis also called Andersson lesion(AL). He was started on a more effective treatment since he had developed this complication despite taking the above mentioned medications. He was started on a medication known as Etanercept Injection. After 4 weeks of starting treatment,the patient showed significant and sustained improvement in pain and mobility. Hence the doctors concluded that in our country where tuberculosis is so common , doctors need to be aware of lesions called andersson lesion to prevent the problem form being misdiagnosed.