© 2018, Derman Medical Publishing. All rights reserved.Aim: Metabolic syndrome (MetS) is characterized by a combination of several cardiovascular risk factors, including central obesity, hyperlipidaemia, hypertension, and insulin resistance. It has been reported that visceral abdominal and epicardial fat tissues have the same ontogenic origin and produce many proinflammatory and proatherogenic cytokines. Irisin is a newly-discovered myokine that plays an important role in metabolic disorders such as obesity, insulin resistance, and type 2 diabetes. The primary aim of this study is to evaluate serum levels of irisin in MetS patients, as well as its association with insulin resistance and disease severity. We also investigated the association between irisin levels and EFT in patients with MetS. Material and Method: Forty-three patients who had MetS without diabetes and 45 healthy individuals were enrolled into the study. Serum irisin levels and echocardiographic EFT values were compared between the groups. Results: Serum irisin levels and EFT values were significantly higher in the MetS group than in the control group (p<0.001, p=0.01, respectively). Irisin levels were positively correlated with insulin resistance (r= 0.33, p<0.01) and other obesity-related anthropometric measurements. Discussion: Elevated irisin levels may represent an adaptive or compensatory response to prevent and ameliorate the metabolic disturbances characteristic of MetS. Further studies are needed to clarify the significance and underlying mechanisms of the elevated irisin levels, and direct evidence is needed to elucidate irisin’s exact role in humans.