© 2020 by The Medical Bulletin of İstanbul Haseki Training and Research Hospital The Medical Bulletin of Haseki published by Galenos Yayınevi.Aim: We aimed to evaluate the prevalence and characteristics of infections, presence of fever and parameters affecting length of hospital stay in hospitalized older adults. Methods: The study included 188 patients aged 65 years and over who were hospitalized in 2017. Demographic characteristics of patients, focus of infection, fever, admission and peak levels of acute phase reactants, culture results, antibiotics used, length of stay and comorbidities were determined. Results: The mean age of the patients was 80±7.9 years and 58% were female. Infection was detected in 53.5% (n=107). Infection was present on admission in 70 patients (65.4%). The most common infections were urinary tract (57.9%), respiratory tract (44.9%), skin and soft tissue infections (10.3%). Fever was present in 44.9%; 89.5% was detected 48 hours after admission. Peak CRP value was found to be the most common parameter that prolonged the hospital stay. Conclusion: For older adults, one of the main causes of hospitalization is infections. Infections prolong the length of hospital stay; so, they should always be taken seriously in older adults, even if there are no typical clinical and laboratory findings.