Objective: Nosocomial infections (NIs) are major health problems with morbidity and mortality. Geriatric patients require intensive care unit (ICU) admission more frequently, and serious challenges occur during treatment. We aimed to evaluate the risk factors of NI and mortality in geriatric patients admitted to the ICU. Materials and Methods: The study was conducted between April 2018 and April 2019 in two hospitals. We prospectively recorded the data on the forms prepared according to daily ICU visits. Results: During the study period, 600 patients were hospitalized in the ICUs. Geriatric patients constituted 446 (74.3%) of the total number. The NI rate was 59% in adult patients and 80% in geriatric patients. The most frequent NI in geriatric patients was pneumonia (42%). Furthermore, the need for mechanical ventilation support, prolongation of hospital stay, total parenteral nutrition, and tracheostomy were statistically higher in geriatric patients with NI. The mortality rate in geriatric patients was statistically higher than in non-geriatric. We found the rates of prolonged hospitalization, NI development, malignancy, and cerebrovascular disease diagnosis significantly higher in geriatric patients than in non-geriatric patients. Conclusion: NI and mortality rate are higher in geriatrics than in adult patients. Pneumonia is the most common type of NI in the ICU. Identification of risk factors regarding NI and mortality in geriatric patients in ICU will contribute to developing strategies for prevention. Keywords: Nosocomial infection, geriatrics, intensive care units.