Background: Leptospirosis, a bacterial disease of worldwide distribution, affects various animals and is considered a zoonosis. It can be transmitted directly or indirectly, mainly through contact with the carrier's urine and entering the body through mucous membranes or skin. In the city of Temuco, there are no epidemiological studies of canine leptospirosis and the country data are scarce. Objective: To determine the prevalence of leptospirosis in stray dogs of the city of Temuco. Material and Methods: In a cross- sectional study, 400 dogs admitted to Temuco Kennel during the year 2011 were sampled. Blood samples were analyzed using a modified commercial ELISA kit. Results: The prevalence of leptospirosis was 21.3%. Positive cases were concentrated in dogs 5 to 8 years of age, independent of gender. Discussion: The high prevalence found demonstrates the need for further studies to better understand the epidemiology of the disease and to establish prevention and control measures.