Dengue Hemorrhagic Fever (DHF) is still a global public health problem, especially in tropical regions, including Indonesia. Correlation between length of stay (LOS) with the cost of hospitalization was significant. Due to the limited government budget available, it is necessary to choose the use of drugs by taking into account quality and cost control. The purpose was to evaluate the cost-effectiveness of class rooms inpatients for reduction LOS. The research design was cost-effectiveness analysis by retrospective study in Private Hospital X in Sidoarjo, Indonesia, for DHF inpatients. The research was conducted at the Inpatient Installation of Private Hospital X, By Pass Krian, Sidoarjo in January-December 2020. The variables were LOS and cost of treatment in the hospital. The study sample was inpatients with mild DHF without comorbid disease. In this study using purposive sampling technique. This study involved 332 subjects. The class I and II trade off with class 3 in clinical outcomes in the form of length of hospitalization (Quadran I). The highest cost was in class I (IDR 3,289,599) compared to class II (IDR 2,985,496) and III (2,985,496). And there was significant difference between the three classes. The lowest length of stay was in class I (4.58 days) compared to class II (4.76 days) and class III (4.8 days). Although there was no significant relationship between the length of hospitalization (LOS). Therefore, it was necessary to further pharmacoeconomic analysis in other DHF therapies including the DHF vaccine.