The clothes will be sold in an online auction on Dec 1.
And in a move designed to involve more of Britain's estimated three million Asians in charity work -- especially during festive times -- the Big B is calling on them to follow his lead.
The Bollywood legend was inspired to donate around 50 items of clothing, including embroidered shirts, suits and jackets to the aid agency after visiting an Oxfam shop in London earlier this year. Oxfam is hoping to raise money from the sale of his items in order to fund the development work that the organisation does worldwide.
"I urge everyone to come forward and contribute very generously to this noble cause," Bachchan said.
"Diwali is traditionally a time for thinking of those in need -- and of getting rid of old clothes and buying new ones and we are hoping Mr. Bachchan's donation will inspire many Hindus, Jains and Sikhs to donate their clothes to their local Oxfam shops and buy fun Diwali gifts from its Unwrapped catalogue," Oxfam said.
Oxfam Unwrapped offers gifts that have been identified by the people that Oxfam works with around the world. They have told Oxfam what gifts they need to make the biggest difference in working themselves out of poverty.
Gifts include items such as fertiliser (£38), seeds (£10), goats (£25), and toilets (£50). More than 1.2 million gifts have been bought since the Oxfam Unwrapped was launched in 2004, supporting people in 49 countries, including Afghanistan, Bangladesh, India, Nepal and Pakistan.
"It is a huge honour for Oxfam to have been given these donations by Amitabh Bachchan, and this generosity underlines why he has maintained such enormous popularity for more than 30 years.
By donating his clothes Big B is helping Oxfam to make a huge difference in tackling poverty, suffering and injustice around the world," said Pushpanath Krishnamurthy of Oxfam.
"We can all do the same at Diwali and by buying Diwali gifts from Oxfam Unwrapped too, we can bring the light of hope to even more people," he said.
Big B's clothes will be exhibited in Oxfam shops so the public has a chance to see first-hand the items the Bollywood legend has donated.