MCP-1 is a potent chemokine with the ability to mobilize and stimulate leucocytes, especially monocytes and macrophages. It is increasingly recognized as an important player in the inflammatory process that is diabetic nephropathy. In this article, we describe its role in inducing renal injury by outlining key studies in animal models and clinical studies of diabetic nephropathy, its association with diabetic retinopathy, as well as its potential use as a prognostic biomarker and as a therapeutic target in the clinical setting.