Abstract: Objective：Improve understanding and management of non-infectious fever in multiple myeloma patients. Methods: Study the differentiation and treatment of a collapsed multiple myeloma case predominantly presented as a high fever，and review the correlative literatures. Results：A 56 year-old male with diagnosed multiple myeloma for 5 years got a high fever when his disease collapsed and widely extra-medullary infiltrated. Examinations for pathogens were negative and antibiotics treatment had no effect. Though the temperature became normal after chemotherapy，the patient died of complication. Conclusion: For myeloma patients，non-infectious fever may be either the admission reason or the presentation as the disease deteriorates. If there is no evidence for infection，chemotherapy should be administrated early.

Key words: multiple myeloma, fever of unknown origin