Our goal was to compare the expression of plasma monocyte chemotactic protein 1 (MCP-1) and the gene polymorphism in patients with pelvic inflammatory disease (PID) and healthy controls. The enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were, respectively, used to measure the plasma MCP-1 level and MCP-1 polymorphism in 70 healthy controls and in 64 patients with PID before and after they received routine treatment protocols. We found plasma MCP-1 was significantly elevated in patients with PID compared to that in normal controls and decreased significantly compared to that in patients with PID after they received treatment. The increased expression of plasma MCP-1 was significantly correlated with the cell counts of white blood cells (WBCs) in blood and the level of plasma C-reactive protein (CRP) of patients with PID before they received treatment. There was no association between MCP-1 -2518G/A SNP and its gene expression levels and PID susceptibility. Elevated plasma MCP-1 could be a biological marker for the diagnosis and to be a new strategy for target therapy of pelvic inflammatory disease.