The efficacy and safety of polatuzumab vedotin combined with rituximab, cyclophosphamide, doxorubicin, and prednisolone (pola-R-CHP) in patients aged ≥ 80 years with untreated diffuse large B-cell lymphoma (DLBCL) remain largely unexplored. In this study, we administered a reduced-dose pola-R-CHP regimen to 38 patients with DLBCL aged > 80 years. Extending the findings of the POLARIX trial in this older individuals’ cohort, we conducted a retrospective analysis to assess the efficacy and safety of the treatment in a real-world clinical setting. After 12 months, the overall and progression-free survival rates were 86.2% (95% confidence interval [CI]: 70.0–94.0) and 78.5% (95% CI: 59.2–89.5), respectively. Although the incidence of febrile neutropenia was relatively high (32%), an increased risk was observed in patients with an average relative dose intensity of < 70%, even with reduced treatment intensity.Notably, none of the patients required a dose reduction of polatuzumab vedotin owing to peripheral neuropathy.Therefore, our findings indicate that a reduced-dose pola-R-CHP regimen may be a viable and effective treatment option for older patients newly diagnosed with DLBCL.