The Janaki Mandir was built in 1911 AD, at a cost of rupees 900,000. In local parlance, the temple is also called Nau Lakha Mandir or Temple of Nine Lakh Rupees.
In 1657, a golden statue of the Goddess Sita was found at the very spot, and Sita is said to have lived there. The legend had it that it was built on the holy site where Sannyasi Shurkishordas had found the images of Goddess Sita. In fact, Shurkishordas was the founder of modern Janakpur and the great saint and poet who preached about the Sita Upasana (also called Sita Upanishad) philosophy. Legend has claimed it that King Janaka performed the worship of Shiva-Dhanus on this site.