Dengue viral fever is an acute febrile illness which is transmitted by Aedes mosquitoes. It presented with body aches, rash, nausea, fever, headache, pain behind the eyes, and vomiting which are common symptoms of dengue. Dengue infections can result in a wide spectrum of disease severity ranging from an influenza-like illness such as dengue fever (DF) to the life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). During the dengue epidemic, we observed number of seronegative DHF. The descriptive retrospective study was conducted in the medical unit at Batticaloa, Teaching Hospital Sri Lanka. We collected data from seronegative dengue patient’s medical records. The leakage was confirmed by periodic abdominal ultrasound and chest X-ray. The data were entered in the validated questionnaire. A total 11 seronegative DHF patients were participated in this study. Out of that 8 were male and 3 were female. Majority of patients were in 22 - 34 age group. The mean age was 26.36 years old. Interestingly, almost all seronegative DHF patients’ lowest platelets were less than 28 × 10⁹/L. The minimum platelets count noted was 8 × 10⁹. Raised liver enzymes were noted in almost all the cases. Even though lowest platelets were reported none of the patients needed platelets or blood transfusion. None of the patients end up with DSS.