To update the study of the association between obesity and treatment response in psoriatic arthritis. Updating a systematic review of clinical trials, prospective or retrospective longitudinal studies and case-control studies in psoriatic arthritis in which obesity was assessed as a predictor of efficacy or toxicity. Risks of bias were assessed with validated scales. A meta-analysis of the results of studies with similar outcome variables and weight measurements was performed. Twenty-one studies were included (6 review of clinical trials, 6 longitudinal studies, 7 registers and one case-control studie), with moderate quality. The risk of achieving an ACR20 response if weight≥100kg was estimated at OR=1.42 (1-2.08) and that of withdrawing treatment in an OR of 1.60 (95% CI: 1.34 - 1.92). There seems to be a greater risk of withdrawal of treatment due to inefficacy and difficulty in achieving remission in patients with psoriatic arthritis if they are obese. Copyright © 2019 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.