Materials and methods 2.1. Patients This retrospective study was approved on January 16, 2020 by the Ankara City Hospital Ethics Committee of the Ministry of Health Provincial Health Directorate (approval number of E1-20-263). Patients were identified via a retrospective examination of the registry entries of 29 Mayıs State Hospital from July 2015 through January Background/aim: Mortality in the elderly population tends to be higher than in all other age groups; the risk factors that predict mortality among those in this age cohort are not fully understood. This large-scale clinical study aimed to identify effective risk factors that predict mortality in the elderly population with a particular focus on age and hospitalization status. Material and methods: We retrospectively analyzed outcomes from patients with clinical follow-up between July 2015 and January 2020 at 29 Mayıs State Hospital, Ankara, Turkey. Patient records with missing or ambiguous data were excluded. Age, sex, length of hospital stay, comorbidities, consultation requests and diagnoses that include infectious diseases were evaluated for their role in predicting in-hospital mortality using binary logistic regression analysis. Primary outcomes focused on factors that had an impact on overall in-hospital mortality in the elderly population. Results: Our study included 11,430 patients; of this group, 39.9% were elderly, which we defined as 65 years of age or older. Risk factors for in-hospital mortality in this cohort included consultation requests (AOR = 1.95, CI (1.53-2.49), P < 0.001) and length of hospital stay of ≥4 days (AOR = 2.49, CI (1.90-3.26), P < 0.001). Conclusion: Elderly patients are at significantly higher risk for in-hospital mortality than are younger patients. Among the factors that may be used to predict the risk of in-hospital mortality in the elderly patient cohort, the most important factor is the length of hospital stay.