A 45-year-old male was admitted to the hospital because of polyuria and polydipsia. After admission, proteinuria and hematuria were found. The kidney function deteriorated and necessitated the initiation of chronic hemodialysis. Examination of the bone marrow revealed multiple myeloma and kappa light chains were found in the urine. The kidney biopsy showed membranoproliferative glomerulonephritis with dense deposits in the glomerular basement membrane.