Standard treatment for elderly patients with relapsed or refractory DLBCL has not been established. CPT-11 has a broad spectrum of anticancer activities including a cytotoxic effect in a variety of malignant tumors. The results of combined treatment with CPT-11 and rituximab have not been reported. The R-CMD regimen was given to elderly patients with relapsed or refractory DLBCL. The safety and efficacy of this regimen were studied. In addition, the serum nm23-H1 level was determined to study whether or not it can serve as a prognostic factor. Thirty elderly patients with DLBCL were studied. The main non-hematological toxicities were infusion-related adverse events. Grade 3/4 hematological toxicity was seen in 19 patients. Following R-CMD treatment, the BNP and troponin T levels did not increase. The CR rate was 57%, PR rate was 17%, 2-year survival rate was 45.2%, and PFS rate was 37.2%. Patients with serum nm23-H1 levels of higher than 80 ng/mL before the treatment showed significantly poorer prognosis. The serum nm23-H1 level of the 30 subjects before the treatment was elevated at 39.4 +/- 41.3 ng/mL, but it significantly decreased only in the subset of patients who achieved CR. The R-CMD regimen was safe in elderly patients with DLBCL. No new signs of cardiotoxicity were observed with this regimen. It was also effective in patients with relapsed or refractory DLBCL who had previously used DXR.