Abstract Leptospirosis is essentially an animal infection by several serotypes of Leptospira and transmitted to man under certain environmental conditions and is fairly widespread throughout India. The most frequent hosts are rodents, especially the common rat (Rattus norvegicus). Most outbreaks of leptospirosis have been reported in coastal regions: Gujarat, Mumbai, Kerala, and the Andaman Islands. A retrospective cross-sectional study was undertaken to find the proportion of leptospirosis from the fever cases in the last 5 years in Coastal Karnataka and to determine the risk factors of leptospirosis. All the Leptospirosis case records from the district office of IMA of the past five years (2007-2011) were collected. Proportion was calculated from the total number of fever cases admitted to the hospital during this period. Case-fatality rate was 12 deaths per 100 hospital admissions. Males are more prone to infection (73.63%). All age groups are affected however maximum case-fatality was seen in the age-groups of 30-39 years (14%) as well as greater than 60 years (13%). Maximum numbers of cases were reported from Mangalore (40.65%). This report highlights the demographic risk factors and the high prevalence of the disease in Coastal Karnataka. Administration and policy making have been found wanting in the area and the incidence can be reduced by increased health education, community participation and better policy development