We report a 50-year-old female patient with diffuse and rapidly progressing splenic calcification. She had developed nephrotic syndrome and been diagnosed with renal amyloid light-chain amyloidosis in 2010. Although she had been given melphalan and dexamethasone therapy and high-dose melphalan followed by autologous blood stem-cell transplantation, her renal function worsened and hemodialysis was started in May 2011. Since November 2011, splenic calcification, probably associated with amyloidosis, had progressed, and diffuse calcification was observed throughout the splenic area in September 2012. During the same period, the patient was hospitalized for thrombocytopenia. Although splenic dysfunction due to calcification was suspected to be the cause of thrombocytopenia, the association between the two could not be established. The platelet count rose with an improvement in hepatic congestion due to reinforced fluid removal during dialysis.