Prince Charles visited some of the poorest districts of Delhi on the second full day of his tour of India.
Charles and Mr Vajpayee discussed 'matters of interest'
The prince met homeless women, watched a play by a group of street children, and also found time to meet with Indian Prime Minister Aral Behari Vajpayee.
The pair held private talks on what officials described as "matters of interest linking the two nations", before addressing a conference for young entrepreneurs.
Charles is spending nine days in India, his first visit to the country since he travelled there 11 years ago with Princess Diana.
While meeting the destitute Indian women, the prince also heard the stories of five individuals described as "invisible leaders of society".
They included a taxi driver from the southern Anhra Pradash state, who last year persuaded fellow cabbies to help Muslim victims of violence in riot-torn Gujarat.
And he met Lali Bai, of Madhya Pradesh, who rebelled against the ancient practice of forcing low-caste Hindus to clean toilets.
Humayun's tomb is the earliest example of a Mughal garden tomb
Street children later performed a play for Charles in a luxurious venue which is normally out of bounds for the city's poor.
Charles last visited India in 1991 accompanied by his then wife Princess Diana.
On that occasion, she travelled alone to the world famous monument to love - the Taj Mahal - and was famously photographed on her own, fuelling speculation about the future of their marriage.
On Thursday Charles was reluctant to be photographed on his own outside Humayun's Tomb, one of Delhi's most beautiful monuments and an architectural forerunner of the Taj Mahal.
He was there to observe improvements to the red-and-white domed monument which was built in the mid-16th century.
Improvement work on pathways, fountains and water channels, which followed original builders' plans, was completed in March.