The present study was undertaken to determine the seroprevalence of dengue fever and dengue haemorrhagic fever (DHF) in patients attending medical clinics or admitted in ICU with febrile signs and symptoms of heamorrhages. 168 (39.4%) out of 426 samples were tested positive for IgM antibodies. Of the 168 positive cases 159 were detected during the months of October and November 2005. Early detection of DHF/DSS can go a long way in managing these patients and to reduce morbidity and mortality specially in DHF and DSS cases.