Leptospirosis is one of the neglected infectious diseases locally widespread and extremely significant in tropical areas due to its great epidemic potential. It is a worldwide public health problem in view of the emergence and reemergence of the disease due to lack of sanitation and negligence, among other factors. In fact, leptospirosis infects more than 1 million people per year, resulting in almost 60,000 deaths. Human infection generally takes place after skin exposure to soil and/or water contaminated with urine of chronically infected mammals. The clinical presentations of the disease vary from a slight fever, goosebumps and flu-like symptoms to the acute forms of the disease. Understanding the main aspects of the disease is paramount due to the many unspecific signs and symptoms as well as frequently mistaken diagnosis. In this article, we discuss the epidemiological, immunopathogenic, clinical and prophylactic aspects of this condition with the purpose of clarifying an up to date panorama of the subject. KEY WORDS: Leptospirosis; Leptospira; concepts; clinical update.