A 68-year-old man was referred to our hospital due to a high fever and pancytopenia. Neither tumors nor infectious lesions were detected. Hemophagocytosis was observed on the bone marrow (BM) smear, although without abnormal cells. Prednisolone therapy was ineffective for the patient's high fever. Later on, we obtained the results of a BM biopsy indicating the presence of infiltration of atypical Reed-Sternberg cells, leading to a diagnosis of HIV-negative primary bone marrow Hodgkin lymphoma (PBMHL). However, the patient died of multiple organ failure before receiving chemotherapy. As the clinical course of PBMHL is rapid, physicians must keep in mind its possibility in similar cases.