Tameside Hospital has given a former patient a Mr Happy window from the demolished children's unit.
Jack Shepherd, 12, was presented with the painted window which overlooked the reception of the children's unit.
A regular at the unit since birth, he was upset when he heard the window, which is painted with Mr Men character Mr Happy, would be destroyed.
However, it was saved by receptionist Linda Axon, who has given it to the schoolboy to hang in his own home.
The Mossley Hollins High School pupil has been treated for several conditions at the unit since birth.
He said he had been disappointed when he heard the Stamford Building was being demolished and had asked Ms Axon to make sure the window wasn't destroyed.
"I never expected anything to come of it," he said.
"We'd been joking about it, but I realised afterwards I really did want it and I'm just so grateful that she arranged it for me."
Ms Axon said that she was driven to save the window after realising how it represented a large amount of time in the boy's life.
"The window is something he will have seen on every clinic visit," she said.
"When I told him his next appointment would be in the new unit, he said it was such a shame the window would be lost and it would be good to have a memento to remember the place by.
"I thought 'there's a lot of things you can't do for people but here's something I could try and do', so I made a call.
"Knowing we've made Jack happy makes me happy."
The schoolboy said he planned to hang the window in the games room being built in his mother's cellar as a reminder of his time at the unit.
"All the staff at Tameside are really helpful, so I have some really good memories," he said.
"It'll be great to go into this room at home and see the window and think about that."