A public appeal was released after Stephen Lopes, who has learning difficulties, went missing from his home in Hillside Road at around 7.30pm on Wednesday (February 8).
Mr Lopes was last seen getting into a van in Allenby Road at 7.50pm, according to the Metropolitan Police.
He is described a man of Asian appearance, slim, and was only wearing his underwear when he went missing but is now thought to be wearing a light grey v-neck woollen jumper, brown trousers and white Puma trainers with a dark stripe.
Mr Lopes has not gone missing before and does not have any money with him, police said.
A police helicopter was used in the search for Mr Lopes.
Anyone who can help is asked to call Ealing Police on 07825 114 094 or get in contact through Twitter using @MetCC.
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