Jatiya Party Chairman went to Delhi on Sunday on a four-day visit at the invitation of Indian government.
Ershad along with some party senior leaders, including its secretary general Ruhul Amin Hawlader, left Hazrat Shahjalal International Airport for New Delhi by a flight of Jet Airways around 10am, said a press release.
He is scheduled to return home on July 25.
Senior Jatiya Party leaders saw their chairman off at the airport.
Party insiders said Indian High Commissioner to Bangladesh Harsh Vardhan Shringla recently met Ershad at his residence, and handed him over a letter of invitation of the Indian government.
They said Ershad is expected to hold meetings with top Indian government officials and BJP leaders during the visit, and discuss various issues relating to mutual interests of the two countries and the next general election.