Leptospirosis is probably the world’s most widespread zoonosis of global importance. It occurs in both developed and developing countries and large outbreaks have been reported from all over the world. Leptospirosis is now being recognized as a re-emerging infectious disease. Understanding the epidemiology of this infectious disease is a critical step for designing interventions and consequently diminishing the risk of leptospirosis transmission. This article reviews on the epidemiological features of leptospirosis. Moreover, depending on these epidemiological data preventive measures are being suggested.