Background. Typhoid fever is a common health problem in developing countries. Antibiotics are used to treat typhoid
fever which is caused by a bacterial infection. Selection and use of appropriate and rational antibiotic therapy can
determine a success in treatment to avoid bacterial resistance and minimize drug side effects. This study aims to
determine the rationality of the use of antibiotics in adult patients diagnosed with typhoid fever in the Inpatient
Installation of X Hospital in Yogyakarta. Method. Non-experimental research with descriptive observational research
design and retrospective data collection. The sample of this study was inpatients with a diagnosis of typhoid fever and
was recorded at the X Hospital Medical Records Installation in Yogyakarta for the period January 2016 - December
2017 which was included in the inclusion criteria. Result. Data taken came from 75 medical records that were included
in the inclusion criteria. Patients were dominated by female patients as many as 64% and the adult age range was 18-
30 years. The single most widely used antibiotic was levofloxacin in 27 cases (36%). The use of antibiotics with the
right indication was 75 patients (100%), the right type was 75 patients (100%), the exact duration of administration
was 64 patients (85.33%), the right dose was 73 patients (97.33%), the right interval was 73 patients (97.33%) and the
right route of administration were 75 patients (100%). Conclusion. The rationality of using antibiotics is good with
accuracy> 75%.