An 84-year-old man, who became the oldest person in the UK to donate a kidney while still alive, has started mentoring organ donors at the hospital where he underwent surgery.
Nicholas Crace, from Overton in Hampshire, is the oldest "altruistic" kidney donor and will never meet the recipient of his organ.
He has produced a pamphlet about his experience as an organ donor.
He has also been offering support at Queen Alexandra Hospital in Portsmouth.
"I'm talking to people who are thinking of giving a kidney and thinking of going through the process at the hospital - just to tell them what it's like and to reassure them that there's nothing to be worried about.
"I don't begin to think that I can advise them in any way - that's the job of the medicos..."
Mr Crace, made the decision to donate last year, aged 83, in the months after his wife Brigid died.
He said he was no longer able to donate blood after turning 70 and when he looked at donating bone marrow he found out he needed to be under 40.
However, there is no age limit for kidneys, even "from somebody as ancient as me", he said.
Mr Crace said the "real heroes" were those with failing kidneys.
He said: "They are left to lead a life coloured by perpetual illness, hoping all the time that one day they will win the lottery and get a new kidney.
"When I realised how easy it could be to change their lives I felt ashamed that I did not think of donating a kidney long ago.
"And like many donors before me, I wish that I had another one to give."