We treated elderly patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) using a CMD (CPT-11, mitoxantrone [MIT], dexamethasone [DEX]) regimen and studied its safety and efficacy. The subjects were 70-79-year-old patients with relapsed or refractory PTCL. CPT-11 at 25 mg/m2 on days 1 and 2, MIT at 8 mg/m2 on day 3, and DEX at 40 mg/day on days 1-3 were administered once every 3 weeks, and this was performed for six cycles. Eleven (37%) of the 30 patients achieved complete remission and seven patients (23%) achieved partial remission. With a median follow-up period of 32 months, the 3-year survival rate was 28.2% and the 3-year progression-free survival rate was 17.5%. The main adverse drug reaction was hematological toxicity and there were no deaths related to the treatment. B-type natriuretic peptide and troponin T levels did not increase after the treatment and none of the patients showed electrocardiogram or echocardiogram abnormalities. Our results indicate that the CMD regimen is safe in elderly patients and no cardiotoxicities developed as a result of this regimen. In addition, it was effective in patients who had previously been treated with doxorubicin and good treatment results were obtained in elderly patients with relapsed PTCL.