Malcolm McIndoe from New Milton was last seen today on Ashley Road at around 12.30pm.
Officers say they have been carrying out “extensive enquiries” to try and locate the 61-year-old, but they remain “extremely concerned” for his welfare.
Malcolm is white, six foot tall, of average build and has blonde hair.
He was last seen wearing a khaki green parker jacket with a fur hood, a grey, white and black jumper, dark coloured jeans and black shoes
Hampshire police said: “Have you seen missing Malcolm McIndoe from New Milton?
“If you think you’ve seen Malcolm since he went missing or think you might know where he is now, please call us immediately on 999 quoting 44250120763.”