Anti-tumour necrosis factor (TNF)-alpha agents promise better disease control for treatment of inflammatory arthritides which are resistant to classical disease-modifying treatment and provide better functional outcome. But these agents are not free of adverse events. The exact relationship between use of anti-TNF drugs and development of demyelination cannot be established yet. Here we present a case of a 36-year-old man who developed demyelination in the cervical spinal cord while he was being treated with etanercept for ankylosing spondylitis.