Platelet-derived growth factor (PDGF) is a pleiotropic cytokine, that is synthesized by various resident renal cells and also by infiltrating cells. The best established role for PDGF in the kidney is the mediation of glomerular mesangial cell proliferation. There is also evidence to suggest an involvement of PDGF in the regulation of renal extracellular matrix turnover, the chemoattraction of mesangial cells and/or other cells to sites of injury, the regulation of glomerular hemodynamics, and lipoprotein uptake in the glomerulus. The first studies investigating the efficacy of anti-PDGF therapy in glomerular disorders point to a potentially novel approach to treat progressive renal disease.