Experimental studies have suggested an important role for abnormal lipid metabolism as an integral factor in modulating progressive renal damage. Dietary induced hypercholesterolemia induced relatively modest glomerular injury. However, in the presence of reduced nephron population or in the presence of underlying renal diseases, such as diabetes, nephrotic syndrome, and hypertension, nephron injury can be markedly exaggerated. These experimental results suggest that an important interaction may occur between renal disease and the occurrence of abnormalities of lipid metabolism. Additional support for the role of lipids in progressive renal injury can be obtained from studies in which pharmacological interventions reduced circulating lipids and this led to decreased glomerular damage. The mechanisms whereby lipids may amplify glomerular injury are not completely understood but may include an interaction with macrophages, alteration in vascular and mesangial functions, changes in production of mediator substances or alterations in membrane fluidity. Local glomerular modification of lipoproteins could also occur and contribute to the development of glomerular pathologic changes. Clinically, few data are available that provide insights into the potential role of renal-related lipid abnormalities in the progression of human renal disease.