Renal failure is a common complication of multiple myeloma, because the kidney is a major target organ for the deposition of paraproteins such as Bence Jones protein (BJP), light chain fragment of monoclonal immunoglobulins, secreted by plasmacytoma. There are three forms of renal involvements related to multiple myeloma. The most common form is cast nephropathy ("myeloma kidney") due to precipitation of BJP combined with Tamm-Horsfall protein in the distal nephron. Other two forms are amyloid nephropathy and light chain deposition disease (LCDD). Renal failure is usually arising from myeloma kidney and is exacerbated by many other factors, for example, concurrently imposed chemical agents. In this manuscript, the mechanism of renal failure mainly due to myeloma kidney and its managements are mainly described.