The singer, whose real name is Alecia Moore and her daughter Willow, 12, stopped by the oncology ward at the Royal Children's Hospital on March 11.

"It's been 22 years since I first visited families at the Royal Children's Hospital, and it was a privilege to return to [the hospital] this week," Pink said on Instagram, alongside a video montage from her visit.

"Thank you to everyone who spent time with Willow and me. Thank you for sharing your stories and letting us play you a couple of songs. We won't forget this day."

The video showed Pink and Willow singing their song Cover Me In Sunshine to the children and their families, meeting patients, parents and signing handmade cards.

The visit was organised by the charity Challenge, which supports children with cancer and their families.

Challenge CEO Dave Rogers said he had been working with Pink since her first visit to the hospital 22 years ago and recently reached out to the singer who said she would be happy to do it.

"I've been doing this for 42 years and I have to say she is one of the best people - she has so much empathy and understanding," he said.

"She was lying on the ground, sitting on the floor with the kids at their level and when one of the mums cried she gave them a hug and held onto them."

Mr Rogers said visits from celebrities such as Pink were for the benefit of both the children and their families.

"It's about breaking up heavy treatment, giving them some enjoyment and an opportunity to meet their heroes," he said.

Pink is coming to the end of her six-week Australian and New Zealand leg of the Summer Carnival tour.

Her final shows are in Sydney on March 16, Brisbane on March 19 and Townsville on March 22 and 23.

The singer said she was "so happy" to be back in Australia describing it as a "home away from home" when she arrived in February.