Aim: The importance of age as a prognostic factor in aggressive non-Hodgkin’s lymphoma (NHL) remains controversial. It is not clear whether age is an independent factor or reflecting the limited physiologic reserves of the patients. Methods: We retrospectively analyzed prognostic factors according to age (≤60/>60) in 201 patients with aggressive NHL treated at our institution between 1989 and 1998 years. An ageadjusted prognostic index was used for younger and older than 60 years patients with aggressive NHL in order to give 5 years survival analysis. Results: Seventy-four (37%) of the patients were older than 60 years and 40 of these were male (54%). Older patients presented with more advanced disease than younger patients (p=0.01). Median follow-up in younger and older patients were 37.6 (range 1-120), and 20.8 (range 1-58) months, respectively. Median survival in younger and older patients were 75 months and 29 months, respectively (p=0.0001). Five years overall survivals rates in younger and older patients were 52% and 40%, respectively (p=0.036). There were significant differences in the median survival according to prognostic factors [sex, performance status (PS), B symptoms, stage, bulky disease, extra-nodal involvement site (ENI), histologic grade, response to treatment, serum lactate dehydrogenase (LDH), β2-microglobulin and albumin levels)] between the two age groups in univariate analyses (p=0.001). In the multivariate analyses response to treatment (complete response and not complete response) (p=0.005), and performance status (p=0.04) retained significant as prognostic factors for overall survival (p=0.001). In patients younger or older than 60 years, age-adjusted prognostic index based on tumor stage, serum LDH levels, PS, and ENI identified four risk groups with predicted five-year survival rates of 56%-38%, 42%- 42%, and 0%-38%. Conclusion: Elderly patients have a poor outcome than younger patients but age alone is not sufficient to discriminate patients with a poor outcome. However, achievement of complete response and performance status are additional important prognostic factors. Response to treatment and PS may define a subgroup of patients with a poor outcome between the two age groups.