Objectives: To assess the association between obesity, control of inflammatory activity and increased adverse effects in psoriatic arthritis (PsA) with disease-modifying anti-inflammatory drugs (DMARD). Methods: A systematic literature review was performed using MEDLINE and EMBASE databases following the guidelines of the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) consensus statement. Studies were selected if they included patients with PsA, obesity was studied as a predictive factor, and the outcome was adverse effects, including efficacy failure. Quality was assessed using an ad hoc risk of bias tool. A qualitative analysis was carried out by type of study and study population, quality and specific results. Results: We found 1043 articles, discarding most of them on the basis of title and abstract. Ten articles were studied in detail and finally excluded three. The majority concluded, with statistically significant results, that in patients with PsA and treated with TNF alpha. inhibitors (TNF alpha i), obesity is associated with poorer chances of achieving and maintaining a minimal disease activity, higher treatment discontinuation rates, and lower skin response. Regarding conventional synthetic DMARD, a trend toward a moderate increase in transaminases with methotrexate (MTX) was observed in obese patients with PsA. Conclusions: Obesity is a negative predictor of clinical response in patients with PsA being treated with TNR alpha i. Except MTX hepatotoxicity, no other adverse effects, either with TNR alpha i or other drugs, were found in relation to obesity in PsA. (C) 2016 Elsevier Espalia, S.L.U. and Sociedad Espaliola de Reumatologla y Colegio Mexicano de Reumatologla. All rights reserved.