BACKGROUND: Several inflammatory mediators have been proposed to contribute to the pathogenesis of atherosclerosis. The aim of this study was to evaluate the quantitative expression of pro-inflammatory cytokines in un-stimulated peripheral blood mononuclear cell of patients with coronary artery disease (CAD). METHODS: Interleukin-1 beta (IL-1β), tumor necrosis factor-alpha, and interferon-gamma (IFN-γ) gene expression were evaluated in angiography confirmed patients with and without CAD in a case-control study using quantitative real-time polymerase chain reaction. RESULTS: A significant increase (P = 0.030) in IL-1β gene expression was found in patients with CAD [median interquartile range (IQR) = 4.890 (6.084)] compared to patients without CAD [median (IQR) = 1.792 (3.172)]. Despite the increase in IFN-γ gene expression in patients with CAD [median (IQR) = 1.298 (3.896)] versus patients without CAD [median (IQR) = 0.841 (2.79)], there was not statistically significant difference (P = 0.990). CONCLUSION: Our results provide evidence for possible association between IL-1β and development of atherosclerosis as a crucial cytokine that induce a network of signaling pathways. This finding if proved in future would suggest IL-1β as a potent therapeutic target in CAD.