We report a 63-years-old woman who developed a nodular lesion in right upper lobe (RUL) of lung after achieving a partial response with salvage chemotherapy for relapsed non-Hodgkin's lymphoma (NHL). Previously, she had been diagnosed as NHL and tuberculous lymphadenitis resulting a complete response with 8 cycles of CHOP regimen and anti-tuberculosis medication for 1 year. CT scan of the chest showed an irregular marginated soft tissue density in RUL with internal punctate calcifications and this lesion was difficult to discriminate between pulmonary tuberculosis and parenchymal involvement of NHL. Because the pulmonary infiltrations progressed despite empirical anti-tuberculosis medication, we performed bronchoscopic biopsy, showing diffuse large B-cell lymphoma. Thereafter, the pulmonary infiltrations were markedly improved with salvage chemotherapy. However, she died of refractory NHL despite high-dose chemotherapy with autologous peripheral blood stem cell transplantation.(Korean J Med 62:109- 113, 2002)