Outcomes in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) are poor. Loncastuximab-teserine (Lonca) is an antibody drug conjugate (ADC) which was FDA approved for R/R DLBCL patients who have received at least 2 prior lines of therapy based on the LOTIS-2 trial. However, there are limited data regarding its efficacy in the real-world setting (RWS). This retrospective study included 21 US centers and evaluated outcomes of patients with R/R DLBCL treated with Lonca. Our analysis includes 187 patients with notably higher risk baseline features compared to LOTIS-2 including a higher proportion of patients with bulky disease (17% vs 0%), high-grade B-cell histology (HGBL) (22% vs 8%), and increased number of prior lines of therapy (median 4 vs 3). The complete response (CR) rate was 14% and overall response rate (ORR) was 32%. Median event free (EFS) and overall survival (OS) were 2.1 and 4.6 months, respectively. Those with bulky disease and HGBL had significantly worse outcomes, and those with non-germinal center cell of origin and CR to most recent line of therapy demonstrated superior outcomes. In summary, in this largest retrospective cohort study of Lonca in the RWS, the response rates, EFS, and OS were lower than those reported in LOTIS-2, which is likely reflective of its use in higher risk and more heavily pre-treated patients within the real world compared to those enrolled on clinical study.