Abstract Objectives: Historically, African-American/Black patients with bladder cancer have worse clinical outcomes compared with White/Caucasian patients. In the CheckMate 274 trial, nivolumab demonstrated a significant improvement in disease-free survival compared with placebo among patients with MIUC at high risk of recurrence following radical surgery; however, African-American/Black patients were underrepresented (< 1%). The objective of this analysis was to describe the characteristics and outcomes of MIUC patients treated with adjuvant nivolumab across different racial subgroups in a real-world setting. Methods: This US retrospective medical chart review included African-American/Black and White/Caucasian patients with MIUC treated with adjuvant nivolumab following radical resection between 01-Sep-2021 and 10-Sep-2022. Patient characteristics and outcomes were abstracted from the medical charts by treating oncologists. Patient characteristics and landmark survival estimates based on Kaplan-Meier analyses were summarized descriptively. Results: The analysis included 223 patients (African-American/Black: 62; White/Caucasian: 161). A numerically higher proportion of African-American/Black vs White/Caucasian patients, respectively, was male (74.2% vs 66.5%), less than 60 years old (27.4% vs 20.5%), unemployed (16.1% vs 5.6%), and had Medicaid at therapy initiation (14.5% vs 6.2%). Similar proportions in both groups had ECOG performance status 0-1 (82.3% vs 82.6%), received neoadjuvant therapy (58.1% vs 56.5%), and completed adjuvant therapy (67.7% vs 66.5%). The median follow-up time (12.5 months vs 13.1 months) and median duration of adjuvant therapy (11.0 months vs 11.3 months) were comparable. Similar estimates were observed for 12-month overall survival (96.7% vs 91.4%), 12-month disease-free survival (88.3% vs 88.4%), and 12-month distant metastasis-free survival (88.3% vs 88.4%). Conclusions: Despite higher rates of socio-economic risk factors among African-American/Black patients, this real-world study suggests similar effectiveness of adjuvant nivolumab among MIUC patients across African-American/Black and White/Caucasian patient populations. Citation Format: Regina Barragan-Carrillo, Alexander Chehrazi-Raffle, Bruce Feinberg, William S. John, Taavy A. Miller, Sarah Lucht, Prathamesh Pathak, Emily Bland, Sarah Gordon, JaLyna Laney, Andrew J. Klink, Hedyeh Ebrahimi, Nisha Singh, Carmelo Alonso, Miraj Patel, Lisa Rosenblatt, Xin Yin. Racial differences in characteristics and outcomes of adjuvant nivolumab for muscle-invasive urothelial carcinoma (MIUC) in the real-world setting [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr A008.