Louis Jarvis, 83, was last seen close to his home address in Fairmile Road at around 8.30am this morning, Wednesday 21 June 2017.
Officers are concerned for Louis’ welfare as he can become easily confused.
Police have been carrying out searches of the area around Louis’ home and are keen to hear from anyone who knows of his whereabouts.
He is white, around five feet eight inches tall and bald with grey hair at the back of his head. Louis was last seen wearing a grey jacket, blue shirt, grey trousers and brown shoes.
Chief Inspector Heather Dixey, of Dorset Police, said: “We are becoming increasingly concerned for Louis’ welfare and are currently carrying out a number of searches in an attempt to locate him.
“I would urge anyone who has seen him or a man matching his description to contact police urgently.
“I would also ask Louis if he sees this appeal to please contact us or your family to let us know you are safe.”
Anyone with information about Louis’ whereabouts is asked to contact Dorset Police at www.dorset.police.uk, via email firstname.lastname@example.org or by calling 101, quoting incident number 21:147.