Five of 23 patients with recurrent nasopharyngeal carcinoma (NPC) were diagnosed to have bone marrow metastasis. They all had advanced local-regional disease, and were treated with neoadjuvant chemotherapy and definitive radiotherapy after the initial diagnosis. Bone marrow metastasis developed 4-24 months later. The clinical features were anemia (5 of 5), leukopenia (3 of 5), thrombocytopenia (4 of 5), sepsis (3 of 5), tenderness of the sternum (3 of 5), and fever (4 of 5). Patients frequently had elevation of serum lactic dehydrogenase (LDH), alkaline phosphatase (ALK-P), and IgG and IgA antibody titers to Epstein-Barr viral capsid antigen when bone marrow involvement was diagnosed. However, clinical manifestations and laboratory tests were not specific. It is important that three patients had normal bone scans. All five patients had a rapid downhill course; four patients died within 23 days, and the fifth 3 months after the diagnosis of bone marrow metastasis. We concluded that bone marrow was a common metastatic site in NPC patients. Bone marrow metastasis adversely affected patients' survival and required a high index of suspicion for diagnosis. We suggested that bone marrow biopsy should be considered as a routine staging procedure in NPC patients and indicated especially when patients presented with abnormal blood counts, sepsis, bone pain, or tenderness of the sternum. It may be positive in the face of a normal bone scan.