Introduction: Fever is one of the common reasons for OPD as well as in patient admission department. Due to improvements of laboratory facilities & imaging the incidence and etiological profile of fever have drastically changed. Proper history taking and systematic examination remains the gold standard for fever evading diagnosis. Methods: This was a retrospective study conducted at the department of emergency medicine, Aga Khan University Hospital from January to June 2016. Adult patients presenting to Emergency department with acute undifferentiated fever were enrolled. Descriptive statistics were calculated in terms of mean±SD for continuous variables like age of the patients and duration of fever, whereas frequency and percentage were computed for categorical variables like gender and causes of fever. Result: In this study typhoid fever was the most common cause of undifferentiated fever (28.9%) followed by malaria (17.8%), dengue fever (13.3%), Acute gastroenteritis (16.7%), Pneumonia (12.2%), Bronchiolitis (5.6%), Hepatitis (3.3%) and Pharyngotonsillitis (2.2%). Treatment- Enteric fever was treated with Ceftriaxone. Chloroquine was used for treatment of Malaria. Dengue was treated symptomatically and with fluids according to Dengue protocol. If fever persisted even after 6 days of antibiotics, then Azithromycin was added. In the undiagnosed fever category, received empirical antibiotics. Conclusion: Malaria was found to be the most common confirmed cause of acute undifferentiated fever followed by dengue and enteric fever. The provision of accurate epidemiological data will enable resources to be directed towards key areas and will be of practical importance to clinicians