Introduction: The objective of this study was to investigate the prevalence, incidence, and treatment patterns (treatment regimens, switches, duration) for diffuse large B-cell lymphoma (DLBCL) in a real-world setting., Methods: This was a retrospective German claims data analysis of patients with DLBCL diagnosed between January 1, 2012, and December 31, 2020. The prevalence and cumulative incidence of DLBCL were found for 2019/2020. Line of treatment (LOT) and treatment setting from first DLBCL diagnosis to end of follow-up were described. Kaplan-Meier overall survival (OS) estimates since DLBCL diagnosis and start of treatment lines were calculated., Results: Overall, 2633 incident DLBCL cases were identified (median age 75 years, 51% male). Of these, 2119 patients received at least one DLBCL-related treatment (LOT1), and 1567 patients died during follow-up. In 2019/2020, the prevalence and cumulative incidence of DLBCL was 34.8/36.7 per 100,000 patients and 14.0/12.7 per 100,000 patients, respectively. For LOT1, 1922 patients were given a chemotherapy-based regimen (1530 with CD20 antibodies). A total of 403 patients were administered a second line (LOT2), of which 183 patients received a CD20 antibody-containing chemotherapy regimen and 100 patients received stem cell transplantation or chimeric antigen receptor (CAR)-T therapy. Of the 136 LOT3+ treatments, 74 were chemotherapy regimens (54 with CD20 antibodies) and 18 were kinase inhibitors. The median time between treatment lines was less than 6 months. Among patients with at least LOT2, approximately 50% received more than one LOT during the first year after diagnosis. Approximately 25% of treated patients died within 6 months of treatment initiation. Of the 2633 included patients, the median OS from diagnosis was 31.0 months (treated patients: 46.8 months, untreated patients: 3.0 months)., Conclusions: Despite advances in the field, high unmet medical need in DLBCL remains. The treatment landscape is very heterogeneous, particularly in second- or later-line treatments, with few patients receiving potentially curative treatment beyond the first line. Treatment for DLBCL, particularly for transplant-ineligible patients, remains challenging., (© 2024. The Author(s).)