BACKGROUND In the past 25 years, clinical trials have demonstrated the benefits of chemotherapy for patients with aggressive non-Hodgkin lymphoma. The authors analyzed the predictors and outcomes of chemotherapy among elderly patients with lymphoma. METHODS Patients age >/=65 years who were diagnosed with Stage III and IV diffuse large B-cell lymphoma [according to the SEER Summary Staging Manual, 2000] between 1991 and 1999 in the Surveillance, Epidemiology, and End Results-Medicare data base were categorized by treatment: no chemotherapy, a doxorubicin-containing regimen, a regimen without doxorubicin, or chemotherapy not otherwise specified. Among the patients who survived for >6 weeks after diagnosis and who had a chemotherapy regimen specified, logistic regression analysis was used to identify predictors of doxorubicin-based treatment, and Cox proportional-hazards regression was used to analyze outcomes. RESULTS Less than 66% of patients received any chemotherapy in the 6 months after diagnosis, and 42% of untreated patients died within 6 weeks. Older age, congestive heart failure, and other comorbidities were strong predictors of treatment without doxorubicin. From 1991 to 1999, the proportion of patients who received doxorubicin increased from <20% to >50%. Patients who received doxorubicin survived more than twice as long (24.4 months) as patients who did not receive doxorubicin (11.2 months). Survival was no better among patients who received chemotherapy without doxorubicin than among patients who received no chemotherapy. CONCLUSIONS By 1999, doxorubicin-based chemotherapy had gained general acceptance for use among the elderly, although nearly 50% of elderly patients still were not receiving it. Given the clinical trial-based evidence of its benefits, in the absence of specific contraindications, most patients, including the elderly, should be treated with regimens that include doxorubicin.