Most studies concerning therapy and prognosis in diffuse large B-cell lymphoma (DLBCL) are based on highly selected patient material. To evaluate treatment, clinical prognostic factors, and outcome in a population-based cohort, we performed a retrospective study comprising 535 de novo DLBCL patients in western Sweden, diagnosed between 1995 and 2000. The median age was 73 years. Treatment with a curative intent was administered to 376 (70%) patients. The International Prognostic Index (IPI) strongly predicted overall (OS) and progression-free (PFS) survival, but high age (>68 vs < or = 68 years) had no significant influence on response rate (p = 0.86) or PFS (p = 0.14). Male sex had a negative impact on both OS (p < 0.001) and PFS (p < 0.001), independent of IPI. In conclusion, a considerable proportion of the patients did not receive curative treatment, but among those treated, the response and PFS were not influenced by age. As men had lower PFS and OS than women, it seems important that gender perspective be taken into account in future studies.