The efficacy and safety of tolmetin sodium in the management of ankylosing spondylitis are presented in a review of published and unpublished data. In both open and controlled clinical studies, tolmetin was superior to placebo and equal to indomethacin in its capacity to relieve pain, inflammation, and other symptoms of ankylosing spondylitis (AS). Objective and subjective assessments showed that both tolmetin sodium and indomethacin provided significant therapeutic benefits to patients with AS. In AS, the two drugs showed similar adverse reaction profiles. Adverse reactions with both drugs were minimal and predominantly affected the gastrointestinal tract; in most cases these symptoms cleared spontaneously without discontinuing the drugs.