OBJECTIVES:  To determine if obesity is associated with poorer patient-reported outcome (PRO) in patients with Axial Spondyloarthritis (AxSpA). METHODS:  We conducted a cross-sectional study using data of the PREcision medicine in SPondyloarthritis for better Outcomes aNd Disease remission (PRESPOND) registry from a tertiary referral centre in Singapore between 2011-2015. All patients fulfilled the Assessment of Spondyloarthritis (ASAS) 2009 criteria for AxSpA. Demographics, clinical and PRO variables were collected. Patients were divided into three categories: normal (BMI<23 kg/m), overweight (23 kg/m≤BMI<27.5 kg/m) and obese (BMI≥27.5 kg/m), using Asian BMI classification. The dependent variables are Pain Score, Bath Ankylosing Spondylitis Patient Global Score (BAS-G), Bath Ankylosing Spondylitis Disease Activity Score (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Health Assessment Questionnaire (HAQ) and Medical Outcomes Study Short Form 36 version 2 (SF-36). Multivariate regression analyses were performed with these dependent variables and obesity categories, adjusting for confounders. RESULTS: We found that obese patients had significant poorer pain (β: 11.87,