Leptospirosis is a zoonotic disease with worldwide distribution whose causal agent is a gram-negative spirochete of the genus Leptospira and the species to be treated in this case is: L. interrogans, which can affect any animal species and humans. It has virulence faxtors associated with the Leptospira of pathogenic species which can be; endotoxins, hemolysins, phingomyelinase, phospholipase, and surface adhesion proteins. Lipoproteins present in the outer membrane of the bacteria are reported in the literature, among which LipL32 is identified, which is only present in pathogenic species such as Leptospira icterhemorragiae, which is a good candidate for the preparation of both the vaccine and the development of diagnostic techniques. The immunity generated is mainly humoral, the bacterium has an incubation period of 4 to 10 days, it spreads in the liver, kidneys, lungs, placenta and CNS. The aim of this article is to present the different virulence factors involved in the development of the disease.