**Abstract**

Visceral Leishmaniasis (VL) caused by protozoan parasite *Leishmania* is a vector borne disease and infection is limited not to human but also to animals worldwide. For infection identification and prevalence in both *Leishmania* endemic and nonendemic regions, several serological and genetic techniques are used. Although diagnostic techniques and clinical symptoms can establish illness status, it is extremely difficult to diagnose infection in the absence of symptoms. Asymptomatic are healthy people who have an infection but are unaware of it. The epidemiology of asymptomatic Leishmaniasis is critical for its eradication. Only a small percentage of infected people are clinically suspected of having VL, as the majority of them may not show any symptoms and remain asymptomatic. Some asymptomatic infections may go away after a while, or they may linger for years, or they may develop to illness with clinical signs. Asymptomatic infection varies per endemic location, but almost all of them point to this hidden category of parasite infection. It is now critical to understand many factors such as diagnostic markers, genetic markers, and immunological markers along with different risk factors. All of these criteria, as well as some innovative techniques to diagnosing and controlling asymptomatic leishmaniasis, will be covered in this chapter. The main focus will be on asymptomatic condition of Indian Visceral Leishmaniasis, which is caused by *Leishmania donovani* and spreads via female sand fly *P. argentipes* biting. The numerous criteria that play a role in asymptomatic to symptomatic conversion in a specific time period will also be discussed in this chapter.

**Keywords:** *Leishmania*, infection, asymptomatic, markers
