Objective: Ischemia-modified albumin (IMA) is a marker of oxidative stress and hypoperfusion that is usually used for acute coronary syndrome. Patients with sepsis undergo hypoperfusion and multi-organ failure that results in death. This study evaluated the efficacy of the albumin-adjusted IMA (AAIMA) level in the emergency department (ED) to predict the 30-day mortality of patients with sepsis Methods: A retrospective analysis study of patients with sepsis was conducted from June 2018 to April 2019 in ED. The data were obtained from the medical records of the patients, and the blood test results were taken from the initial blood tests at the ED. The data and blood test results of the 30-day survival and non-survival groups were compared. Results: Two hundred thirty-three patients were included. The mean age was 75 years, and the overall mortality was 20.6%. The non-survival group had higher AAIMA levels than the survival group (75.1 U/mL vs. 68.4 U/mL). The area under the receiver operating characteristic curve of AAIMA to predict the 30-day mortality was 0.789 (95% confidence interval, 0.730-0.840; P<0.001), and the sensitivity and specificity of predicting mortality was 68.8% and 78.2%, respectively, after setting the AAIMA cutoff value to 72.9 U/mL. Conclusion: The initial albumin-adjusted IMA on ED admission has potential as a predictor of the 30-day mortality in patients with sepsis.