Abstract Purpose: A considerable amount of uveal melanoma patients present to the emergency department (ED) for a complication related to their primary tumor. However, there is not much research into the primary reasons for these patients to present to the ED and their outcomes. Methods: The Nationwide Emergency Department Sample was queried from the last quarter of 2015 to 2019 to identify patients with a diagnosis of uveal melanoma. Multivariable logistic regression, with patient- and hospital-level characteristics as covariates, was used to identify factors associated with increased risk of in-hospital death. Results: From the last quarter of 2015 to 2019, there were 7,561 ED encounters with a secondary diagnosis of uveal melanoma. Most patients were at least 65 years of age (43.5%), male (52.5%), and a Medicare beneficiary (44.2%), or belong to a family in the 3rd income quartile (25.6%). The median age of these patients was 61 years (IQR: 32-74). Most patients presented to hospitals in the South (40.8%), with a Trauma Level I designation (47.2%), and to a metropolitan teaching hospital (72.6%). The most common diagnosis for presentation to the ED were the following general clinical categories: blood disorders (7.1%), genitourinary tract disorders (5.1%), infections (6.0%), respiratory diseases (9.0%), nervous system disorders (4.8%), endocrine/nutrition disorders (4.3%), and vascular disorders (8.3%). The rate of metastatic uveal melanoma was 5.8%. The rate of in-hospital mortality was 3.6%. In a multivariable logistic regression identified the following clinical categories as factors associated with a higher risk of in-hospital death: infections (odds ratio [OR]=10.22; p<0.001), metastases (OR=10.22; p<0.001), genitourinary tract disorders (OR=7.05; p<0.001), respiratory diseases (OR=3.31; p=0.031), and vascular disorders (OR=3.14; p=0.044). Nervous system, blood, and endocrine/nutrition disorders were not associated with a higher rate of in-hospital mortality. The only demographic variable associated with a higher risk of in-hospital death was being part of the top income quartile (OR=3.10; p=0.14). Conclusion: Physicians have to be mindful of different complications associated with uveal melanoma that can lead to presentation to the ED and possible in-hospital death. Specifically, physicians need to be mindful of infections, metastases, genitourinary tract disorders, respiratory diseases, and vascular disorders in these patients. Citation Format: Alice A. Beneke, Kamil Taneja, Lauren Ladehoff, Kevin Root, Eric Toloza. In-hospital mortality risk factors for uveal melanoma patients in the emergency department [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6480.