"He is stable and under observation," a source said, according to India Today. He was admitted owing to old-age ailments, media reports said.
Doctors of the geriatric department of AIIMS are looking after the 96-year-old former deputy prime minister.
Lal Krishna Advani was the 7th Deputy Prime Minister of India from 2002 to 2004.
One of the founding leaders of the ruling Bharatiya Janata Party (BJP) and a member of the Rashtriya Swayamsevak Sangh (RSS), he was also the Home Minister of India and a recipient of Bharat Ratna.