Atrial Fibrillation (AF) is the most common cardiac arrhythmia and an independent risk factor for stroke among the elderly. A role for inflammation in the atrial remodeling as well as development and recurrence of AF is known.To compare IL-17A between patients with different types of AF and healthy individuals.IL-17A was measured in sera of 112 patients and 107 healthy age/sex-matched controls using ELISA assay. In sera of 26 patients with elevated IL-17A (>1 Pg/ml), CCL5 and CCL18 levels were also measured.IL-17A was significantly increased in patients with AF compared to controls (1.28 ± 3.5 vs. 0.19 ± 0.64 Pg/ml, p=0.001). There was no significant difference in the level of IL-17A between different types of AF. IL-17A was significantly higher in patients with a history of coronary artery bypass graft compared to other patients (p=0.01). A significant positive correlation between IL-17A and CCL18 concentration was found (p=0.001). An increase in the Neutrophil/Lymphocyte ratio (NLR) was observed in patients with elevated serum IL-17A compared to other patients (p=0.006). Male patients showed higher increase in NLR (p=0.007) which was accompanied by a decrease in CCL5 (p=0.000) and a marginal increase in CCL18 (p=0.085) compared to females. There was an increase in CCL5 levels in patients receiving Acetylsalicylic Acid (ASA) therapy (p=0.046).The increase in IL-17A levels is related to the AF pathology mediated by neutrophils and monocytes. The current study signifies the role of immune cells and cytokines in the pathology of AF.