A 65-year-old woman was hospitalized for heart failure and pneumonia in a nearby hospital. She had been previously diagnosed as light chain (AL) amyloidosis and treated with melphalan plus dexamethasone (Mel-Dex), and lenalidomide plus dexamethasone (Len-Dex). She started treatment including antimicrobials and diuretics, but her renal function worsened progressively, and she was transferred to our hospital for nephrological care. She was treated with antimicrobials, noradrenaline, dobutamine, and continuous hemodiafiltration. Her general condition gradually stabilized, and she was switched to intermittent hemodialysis (HD). However, HD was discontinued due to intradialytic hypotension and the development of heparin-induced thrombocytopenia. Her renal replacement therapy was switched to peritoneal dialysis (PD), which enabled good volume control and stable cardiac function. She was discharged and is still in good condition, without serious complications and achieving a considerably better prognosis than was predicted. Our case suggests that PD is an effective modality for patients with AL amyloidosis with heart failure and renal dysfunction.