Abstract: Monocyte chemoattractant protein-1 (MCP-1) has been shown to be a potent chemotactic factor for monocytes. It acts as an important factor in the cytokine network which regulates tumor proliferation. The association between serum MCP-1 level and oral squamous cell carcinoma has not been clarified yet. The aim of this study was to determine MCP-1serum levels in patients with oral squamous cell carcinoma and investigate if it is correlated with clinicopathological features of tumor. Using an ELISA kit, the circulating levels of MCP-1in blood serum of 54 oral squamous cell carcinoma patients with 32 healthy control samples were assessed. The serum MCP-1 concentration in OSCC patients was significantly lower (573.1±238.6 pg mL-1, n = 54) compared with healthy controls (719.7±354.5 pg mL-1, n = 32; p = 0.02). There was no apparent correlation in serum MCP-1concentration with the clinicopathological features such as stage, tumor size, nodal status and histological grade. Serum levels of MCP-1 decreased in patients with oral squamous cell carcinoma but no clear-cut relationship was detected between MCP-1 levels and clinicopathologic factor. These results suggest that MCP-1 may not be a useful marker for recognition of clinical behavior of oral squamous cell carcinoma but further studies is recomended.