Considerable advances in the understanding of renal complications of dysglobulinemia have occurred in the last 10 years. They mostly result from sequence studies of nephritogenic immunoglobulin chains and comparison with sequence database, and from a careful analysis of clinicopathological features including electron microscopy characteristics of immunoglobulin deposits. These advances should help define subpopulations of patients with plasma cell dyscrasia at risk of developing renal complications and to design novel therapeutic approaches. Although renal complications of plasma cell dyscrasias may be considered as anecdotal diseases, understanding their pathophysiology may help dissect the mechanisms of glomerular and proteinuria-induced interstitial fibrosis.