"AAP has registered historic 'maha vijay'. I congratulate Kejriwal on this victory and hope he will fulfil the promises made to the people of Delhi," Ramdev told reporters.
"I hope he will also win the hearts and trust of people by doing good work," he added.
Ramdev, who has been openly praising BJP in the past months, had also supported the anti-corruption movement started by Anna Hazare in 2012.