BACKGROUND: The purpose of this study was to evaluate the clinical features and treatment outcome of patients with primary non- Hodgkin's lymphoma (NHL) of bone. METHODS: A survey of 1,050 NHL patients who had been diagnosed at Korea Cancer Center Hospital between 1989 and 2001 identified 32 patients with NHL involving bone. Of these 32 patients, 22 patients were diagnosed as primary NHL of bone. The clinical data were available in 17 of the patients, and analyzed retrospectively. RESULTS: The male to female ratio was 3.3:1 and the median age was 31 years (range, 16- 52 years). The most common presenting symptom was bone pain of involved site (76.5%) and the most commonly involved site was tibia. Stages at diagnosis were as follows: stage I in 6 patients; stage II in 2 patients; stage III in 2 patients; stage IV in 7 patients. According to the REAL classification, the most common histologic subtype was diffuse large B cell lymphoma. Of evaluable 16 patients, 5 patients had B symptoms. The risk groups accord-ing to International Prognostic Index (IPI) were as follows: low risk in 9 patients, low-intermediate risk in 4 patients, high-intermediate risk in 1 patient, high risk in 2 patients, not evaluable in 1 patient. The first-line treatment modalities were as follows: combined radiation and chemotherapy in 8 patients (1 for palliative aim, 7 for curative aim); chemotherapy only in 4 patients; radiation only in 2 patients; surgery and chemotherapy in 1 patient. Objective response rate to treatment was 93.3% (95% confidence interval; 80.9~100%) and five-year survival rate was 57% (95% confidence interval; 30.5~83.4%). CONCLUSION: Most patients complained bone pain at involved site. The histologic subtype was diverse, but the most common subtype was diffuse large B cell lymphoma. The prognosis is similar to other non- Hodgkin's lymphomas.