Multiple myelomas are the commonest hematological malignancy in adults, next to the heterogeneous group non-Hodgkin lymphomas, and account for about 10% of such tumors. About 21% of the multiple myelomas are associated with higher levels of free monoclonal light chains. This subgroup of patients exhibits high incidence of renal disease manifested by significantly lower estimated glomerular filtration rate, higher incidence of dialysis and significantly shorter survival.We have defined criteria for identification of high risk patients with light chain only as well as intact immunoglobulin myelomas. Kappa and lambda light chain specific criteria have been enunciated for intact immunoglobulin multiple myelomas and the need for development of similar criteria for light chain only myelomas has been identified.