South Wales Police is appealing for information on the whereabouts of 70-year-old William John Williams.
Mr Williams, who has dementia and slurred speech, left his home address at Penygraig, Rhondda at 1pm on Friday, June 25 and has not been seen since.
There is increasing concern for his safety and would appeal for anyone with information on where he is, or any recent sightings to contact us.
Mr Williams is white, of heavy build with short grey hair, and is around 5ft 8in tall. He has a small scar under his lower lip and a black scar on his right forearm.
He was last seen wearing a blue shirt, brown trousers, black shoes and might be carrying a blue jacket.
As he is known to walk to Dinas, Trealaw and sometimes Tonypandy, officers have been making enquiries in these areas as well as checking CCTV and using police dogs to track any possible routes Mr Williams could have taken.
Residents might also see the police helicopter overhead as the search for Mr Williams continues.
If you have seen or have any information in relation to Mr Williams please contact South Wales Police on 101.
