Osteoporosis is frequently associated with Ankylosing Spondylitis (AS). Bone mineral density (BMD) decreased predominantly in patients with active disease. Moreover, conventional therapy, i.e. NSAID seems to have no influence in the bone loss. It has been suggested that local or systemic inflammatory cytokine release might be implicated in bone loss. Monoclonal antibody to TNFalpha in patients with AS demonstrated significant clinical response with significant reduction in the acute-phase reactants ESR and CRP. We evaluated the changes in bone mineral density (BMD) in patients with Spondylarthropathy (SpA) treated with infliximab (a human/mouse neutralising chimeric monoclonal antibody). We included 29 patients. In 6 months, there was a statistically significant increase in BMD both at the spine and total hip. There was an increase in osteocalcin between baseline and week 6. These data suggest a benefit of anti-TNFalpha therapy on BMD in patients with SpA, may be through an uncoupling effect on bone cells.