A 65-year-old man, who is a Jehovah's Witness, was admitted to our hospital due to progressive anemia following a four-year history of biclonal gammopathy of no clinical significance. He was diagnosed with pure red cell aplasia (PRCA) associated with plasma cell dyscrasia. Despite a markedly decreased red blood cell count (hematocrit 5.6%), the patient refused transfusion. He was intravenously administered bolus methylprednisolone. Reticulocytosis and recovery from anemia were observed on day 7 after the start of therapy. Secondary PRCA following plasma cell dyscrasia is a rare disorder; the treatments for this rare condition are discussed.