Smokey the cat spent most of his life comforting at Waikato Hospital.

A cat that spent most of its life comforting sick and dying patients at Waikato Hospital died on Sunday afternoon.

Smokey, 20, had to be put down after being hit by a car in his new hometown, Rotorua.

Anna and Garry Simmons and their children Eion, 3, and Cain, 15-months, had been looking after Smokey for the past four years.

"We think he was hit by a car over the weekend, he passed away at 4.47pm [on Sunday], with his family by his side," said Anna Simmons.

"Garry and I will miss him hugely.

"We knew he had a habit of wheedling himself into people's hearts and we know he will be missed by many."

FROM THE ARCHIVES: Smokey's days of doing the rounds coming to end

The friendly tabby adopted the hospital as his home in 1997, after following his former owner to work.

Waikato DHB communications director Mary Anne Gill said Smokey was owned by a nurse who lived in Horne St and then adopted by the Simmons' in 2010.

"He would follow her to work and hang around the [Menzies building]," she said.

"We are very sad to hear of Smokey's passing but know he had a great family taking care of him."

Smokey had been known to lie with patients on their deathbed's and the hospital Heart Failure Nurse, Cathy Callagher, said he had even helped to regulate one patient's heart rate.

"Smokey jumped up on the bed, made himself at home much to the delight of the patient and her heart returned to normal rhythm," she said.

"I can also recall him accompanying a lady from Medical Day Care Unit up to the Endoscopy Suite on L4 Waiora with a patient.

"Upon arrival in the Endoscopy Suite the nurses discovered the lady had Smokey under the top sheet and had to get him out rather hurriedly before the doctors discovered him there."

The tabby spent his last years at his lakefront home in Rotorua, hunting birds.

"We moved to a space across from the lake and amazingly he still managed to catch things," Anna Simmons said.

"Just the other week he came home with a rabbit head."

Smokey will be a much missed member of the family and his guardians are hoping to bring his ashes back to Waikato Hospital.

"We have got him cremated and we're in discussions with Mary Anne," said Anna Simmons.

"We would like him to be buried or scattered at the hospital because although he lived with us, we were his guardians and the hospital was his home, that's where he chose to spend his time.'