The former Bihar Chief Minister was released after he completed the bail formalities in a Special CBI court here as directed by the Supreme Court.
Yadav came out of the main gate and paid obeisance to the tribal icon statue in jail premises.
"I will go around the country to strengthen the secular forces and Narendra Modi or BJP or RSS will not be allowed to fulfil their dreams," a relieved Lalu told reporters soon after release.
Hundreds of RJD supporters greeted him on his release.
The RJD chief, another former Bihar Chief Minister Jagannath Mishra and 43 others were on September 30 convicted by a special CBI court in the fodder scam case involving fraudulent withdrawal of Rs 37.7 crore from Chaibasa Treasury during the Prasad-led RJD regime.
The RJD chief is scheduled to visit the Deori Temple, about 40 km from here, an RJD spokesman said.
After the Jharkhand High Court had rejected his bail plea, he had moved the apex court and obtained bail on Friday last.
Pleading for bail, Prasad, who lost his membership of Parliament after being convicted in the case, had submitted that of the 44 persons convicted along with him, 37 have been granted bail and no one's, except his bail plea has been rejected.