Introduction: With the growing evidence about the role of inflammation on cardiovascular disorders, studies have been focused on inflammatory markers for risk evaluation and disease activity monitoring. The aim of this study was to investigate whether inflammation has a role in idiopathic pericardial effusion (PE) and to reveal its correlation with the disease activity. Patients and Methods: The study population consisted of 107 patients with PE and 35 age-matched and sex-matched healthy volunteers. Each patient underwent a comprehensive clinical evaluation to identify the probable underlying systemic diseases or other potential causes for PE. Results: High-sensitivity C-reactive protein levels (hs-CRP), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) (p< 0.001 for each) were significantly higher in the PE group than in healthy volunteers. The patients with PE were divided into three subgroups according to the amount of PE. hs-CRP, NLR and PLR significantly correlated with the amount of PE. In the multivariate logistic regression model NLR (OR 1.363, 95% CI 1.026-1.809; p= 0.033) and hs-CRP (OR 1.090, 95% CI 1.030-1.152; p= 0.003) remained as independent predictors of severe PE in patients who have PE. Conclusion: hs-CRP, NLR and PLR may be used for disease activity monitoring, treatment response evaluation and risk stratification of patients with PE.