Kaitlin Taylor, 11, sent the heartbreaking plea in red felt-tip pen to Father Christmas in her last desperate bid to stay alive.
Just weeks later a miracle happened and the 11-year-old got a call from doctors telling her they had found her a kidney.
She was rushed into the Royal Hospital for Sick Children in Glasgow for an emergency kidney transplant which has changed her life.
Kaitlin, from the city's East End, was born with only one kidney which had 30% of its function capacity, so she was extremely ill. From that moment on, she had to be fed through a tube and was constantly sick.
Kaitlin was so ill she couldn't go to school, go out to play with her pals or eat a meal, and spent hours hooked up to a kidney dialysis machine.
But her transplant has turned her life around and she's now got the energy to go swimming and eat her favourite meal of steak pie and broccoli.
Kaitlin told the Evening Times of her joy when she discovered her Christmas wish had come true.
She said: "It was the best day of my life. I'll never forget it. I was very happy but scared at the same time.
"My mum came into my bedroom to tell me banging pots and pans and jumping around with excitement.
"I feel different now because I can eat my favourite food, play with my friends and go to school just like everyone else."
Her proud mum Ann-Marie, 59, described her daughter as "absolutely amazing" and a "real inspiration".
The former nurse said: "Before we got the call from the hospital to tell us they had found Kaitlin a kidney it was touch and go.
"I thought I was going to lose her because she was extremely ill. Her condition had really deteriorated and I was worried she might not make it. Doctors told us she had a bad infection and even the dialysis wasn't helping her at that stage.
"But Kaitlin is a wee fighter. She never gives up and never complains.
"That Christmas she sat down and wrote this letter to Santa asking for a kidney. She knew she was really ill and I think it was her last hope.
"We couldn't believe it when her Christmas wish came true only a few months later. It was a miracle.
"I was emotional when we got the call from Yorkhill - like a bolt from the blue they had found Kaitlin a kidney.
"I will remember the day we got that call from the hospital for the rest of my life. I couldn't believe it.
"I was so happy I grabbed some pots and pans and started banging them as we went into Kaitlin's room to break the news. She was delighted.
"I always had a suitcase packed just in case so we went straight away.
"When she went into hospital to have the transplant I was really upset. I was crying because I was worried she might not be strong enough to make it through the operation.
"Kaitlin asked me 'will I be alright mum?' I told her she would be fine because I have total faith in the doctors at Yorkhill.
"I knew my girl would be safe in their hands because they are the best in the world.
"Since then Yorkhill's renal team and nurses have been taking good care of her. Kaitlin wouldn't be alive today if it wasn't for them.
"They have been with us every step of the way and we couldn't have done it without them.
"The change in Kaitlin since the transplant is remarkable.
"She has got her life back and is loving every minute of it."
Kaitlin wrote her letter to Santa in Christmas 2011 and had her transplant just months later.
She still has to visit Yorkhill for regular check ups and will be on medication for the rest of her life but her mum says it's a small price to pay. Ann-Marie also praised the support they have received from the Kidney Kids Scotland charity.