James Miller, 72 years old, was last seen by his wife at their home address in the N16 postcode area of Hackney.
He went missing on Monday 4 February, between 1:30am and 4:00am.
James is described as a light skinned black man, 5 feet 10 inches tall, with a medium, frail build. He has short grey hair.
He is believed to be wearing black jeans, black trainers and a green and blue checked pyjama top.
A picture of James can be seen below:
There is concern for his safety and whereabouts.
Anyone who has seen James is asked to contact Hackney Police on 101.