Objective To investigate the related factors for in-hospital mortality in elderly patients with severe acute pancreatitis (SAP). Methods Clinical data of 314 SAP patients admitted to the Center for Pancreatitis, Department of Hepatobiliary Surgery in the First Medical Center of Chinese PLA General Hospital from January 2015 to December 2019 were retrospectively collected and analyzed. The patients were divided into aged group (≥60 years) and non-aged group (<60 years). Their conditions and prognosis were compared between 2 age groups. For the aged group, they were further assigned into death subgroup and survival subgroup. The differences were compared and the related factors for mortality were analyzed. R Studio. Inc. Version 1.1.456 was used to make statistical analysis. Wilcoxon test and Chi-square test were adopted for intergroup comparison, and logistic regression analysis was employed to analyze the related factors for death in the elderly SAP patients. Results The aged group had significantly higher mortality rate (34.5% vs 16.9%), longer length of ICU stay[2(0,11) vs 6(1,15)d], higher surgical intervention rate (73.6% vs 58.2%), and fewer undergoing necrosectomies, and larger proportion of respiratory (60.0% vs 32.4%) and circulation supports (58.2% vs 32.4%) when compared with the non-aged group. For the elderly SAP patients, age and requiring renal replacement due to renal failure were independent risk factors for in-hospital mortality. Conclusion The elderly SAP patients have poor prognosis. Special attention should be paid to them for the support of vital organ function.