The aim of the paper is to study the history of Vishkanyas in India from ancient upto medieval times ,Vishkanyas were the poisonous celibate assassins who actually existed according to the sources like Chanakya’s Arthshastra and some local Marathi sources of Mughal emperor Akbar suggested that Vishkanyas actually existed and were used as a secret weapon to kill people .This paper also attempts to discuss the scientific possibilities of Vishkanays and the secrets behind it. The Vishkanya (Sanskrit विषकन्या)(English: Poisonous young lady) were young ladies supposedly utilized as professional killers, regularly against intense adversaries.Their blood was purportedly toxic to different people, as known from the old Indian treatise on statecraft .Arthashastra, composed by Chanakya (Kautilya), a counsellor to the principal Mauryan Emperor Chandragupta . A Hindu folklore message, The Kalki Purana, says that they can slaughter a man just by taking a gander at them.