Introduction: Bacterial and Viral infections are often hard to be distinguished in daily clinical practice. Biological markers obtained from a routine examination play an important role to minimize time in providing diagnose and giving therapy. Recently, the use of Neutrophil-lymphocyte ratio (NLR)and platelet-lymphocyte ratio (PLR) is greatly considered to differentiate types of infection found in the patients presenting with fever. Material and Method: This study uses prospective cohort study design and involves patients presenting with fever who are admitted in the hospital. The initial NLRand PLR is examined and categorized into types of infection foundi.e. grade I DHF and grade II DHF. The ANOVA test and t-test are performed to find out the difference among study groups. Result: In the present study, a total of 104 patients were clinically suspected on the admission as dengue fever, 80 of these were serologically confirmed dengue positive. A 44 of these were grade IDHF infections. The average age was 42.1 years, the range being 23-65 years. Based on 2009 WHO clinical criteria, 34 were identified as Dengue with warning Sign, 27 as Dengue Without warning Signs while 19 were identified as Severe Dengue. Some of the frequently observed clinical features were fever, headache, thrombocytopenia, leukopenia and rashBoth NLR and PLR correlated severity of DHF.NLR and PLR had significantly higher values in grade II DHF patients. Conclusion: Neutrophil-lymphocyte ratioand PLR have benefit to predict diagnosis for the patients presenting with a fever. Bacterial infection is associated with the high value of NLRand PLR generally has a lower value in viral infection cases.