A 51-year-old man was admitted with systemic lymph node adenopathy. Hematological examination on admission revealed leukocytosis, and 35% of leukocytes were classified as pathologically abnormal. Moreover, increases in serum IgM (kappa type) and plasma viscosity were recognized. Following biopsy of the lymph node, a diagnosis of non-Hodgkin's lymphoma (diffuse, mixed type) was made. After the implementation of combination chemotherapy, the results of hematological and physical examinations improved. As the nadir receded, serum IgM increased once more, and nine courses of chemotherapy were necessary. In order to promote steady progress toward discharge, etoposide therapy was instituted. Subsequent low-dose etoposide therapy at 50 mg/day rarely resulted in an increase in serum IgM, subjective or objective adverse effects, except for mild lekopenia. After discharge the patient was placed on intermittent etoposide therapy and remained in a state of remission for approximately 11 months. Fortunately, his rehabilitation was successful, and he returned temporarily to his former position. The 2nd remission has continued for approximately seven months. Consequently, long-term low-dose etoposide therapy is speculated to be a significantly useful therapeutic technique for intractable malignant lymphoma.