Dengue is a major health problem in many parts of tropical world. Dengue is caused by infection with one of the four serotypes of dengue virus (DEN 1-4) which are arboviruses belonging to the Flaviviridae family and are transmitted by mosquito principally Aedes aegyptii. Typhoid and malaria are the two diseases which are caused by different organism, one a gram negative bacilli and the other a protozoan and transmitted by different mechanisms. Dengue, Typhoid and Malaria share rather similar symptamatology. To know the prevalence of Dengue infection in and around Davangere, to determine the incidence of co infections i.e. malaria and typhoid fever with Dengue in Davangere. Total of 160 serum samples were studied from July to December 2010 in Department of Microbiology JJM Medical college, Davangere. All the samples were tested for IgM Dengue ELISA and IgG Dengue ELISA. The same samples were also tested for Rapid Malaria Antigen detection and slide agglutination test for rapid detection of Salmonella typhi. Out of the 160 serum samples studied 74 samples were positive to IgM Dengue ELISA and 50 samples were positive to IgG Dengue ELISA. 20 were tested positive to Malaria by Malaria Antigen strip test. 10 samples were positive to IgM Dengue ELISA and Malaria Antigen strip test. 8 samples tested were positive to slide agglutination test for rapid detection of Salmonella typhi. IgM Dengue ELISA and slide agglutination test for rapid detection of Salmonella typhi were positive in 3 samples. Malaria and dengue must be suspected in febrile patients living in or returning from areas endemic for these infections. Dengue and typhoid fever often present with mimicking symptoms especially in early stages of typhoid.