Father-of-three John Bowkett went missing from his home in Welfare Road, Doncaster, on July 12, 1992.
His family have said they supsect foul play. A bank account belonging to John, who was 37 when he went missing, has not been used since he disappeared.
Joy Bowkett, John's sister, said: "We, John’s family, have not seen or heard anything from him since he disappeared. Foul play is suspected and we believe someone knows what happened to our brother. We hope that one day we can bring him home where he belongs.
"Since John has gone, we have lost our mum and dad, plus a brother and sister have passed, all without knowing what happened to him.
“I will never give up, somebody knows something, we just need to know where he is. Then the person who passes on information can carry on living the rest of their lives like they have done for the last 30 years.
“John has still got a very large family including three of his own children, grandchildren, two sisters, five brothers, nephews and nieces. He is a much-loved and missed uncle, dad, grandad and friend to many.”
John is described as being about 5ft 10in and of medium build, with blue eyes. He had brown collar-length hair and a moustache at the time of his disappearance, and has a scar on one of the fingers on his right hand.
He worked at Brodsworth Colliery and became known locally for fixing fridges after the pit closed.
John had two children with his first wife before they separated, and she later died suddenly. He remarried and had a daughter, who was only two years old when he vanished unexpectedly.
Following his disappearance there were reported sightings at a pub in Whitley Bay and a tram stop near Crystal Peaks in Sheffield, but these were never corroborated.
Anyone with information is asked to call South Yorkshire Police on 101, or Crimestoppers, free and anonymously, on 0800 555 111.
Alternatively, you can phone or text Missing People on 116 000, or email [email protected], quoting reference 93-000035.