Separated Twins Nima and Dawa Leave Hospital

Twins Nima and Dawa have left Royal Children's Hospital in Melbourne.

Bhutanese twins Nima and Dawa have left a Melbourne hospital as individual "cheeky" girls, weeks after life-changing surgery to separate them.

The 15-month-old sisters, who had spent their lives joined at the torso, left Royal Children's Hospital in a pram on Monday with their mum Bhumchu Zangmo, after successful surgery on November 9.

Lead paediatric surgeon Joe Crameri said the girls were recovering well, but there was no date set for their return to Bhutan.

"The twins have made an excellent recovery and they are now starting to act independently and move around," Dr Crameri told reporters.

Nima and Dawa leaving hospital with their mother, Bhumchu Zangmo (Image AAP)

"I was pleased to see they were somewhat smiling (today)."

He said the staff had seen the "two remarkable girls" transform since becoming independent.

"Girls who started off really attached and bonded to another, but ultimately frustrated with one another," Dr Crameri said.

"We saw them became incredibly anxious after the surgery once they knew their other twin was not immediately in front of them.

Nima and Dawa separated and happy (Image AAP)

"Over the last couple of weeks, we have seen them gain confidence, gain independence and gain a lot of strength."

Dr Crameri says being able to stand will be a "work in progress" for the girls as they build up strength and balance.

While they are yet to form full words, Dr Crameri said The Wiggles signature finger move had become their favourite while in hospital.

The surgery was a success (Image AAP)

"They are cheeky. Dawa has turned on me. I thought she was going to be eternally grateful to me for getting her sister off her but she just seems to get grumpy with me," he joked.

"When they are comfortable in their own space, they are very cheeky. They like to replicate The Wiggles."

The former king of Bhutan wrote a letter to hospital chief executive Joe Stanway, thanking staff for changing the girls' lives.

Dr Joe Crameri and Dr Ian McKenzie (Image AAP)

Jigme Singye Wangchuck wrote: "The successful surgery has made it possible for Nima and Dawa to enjoy a happy and meaningful life in Bhutan".

The girls will to travel regional Victoria with their mother to the Children First Foundation's Kilmore retreat to continue recovering, before returning home to family.

The letter from the former king of Bhutan (Image AAP)

"What the two girls need is stimulation of other children being around to challenge them, to give them interest and that will do wonders for the girls," Dr Crameri said, noting one more wound check and a review was expected.

The foundation helped bring the girls and their mother to Australia for the surgery. They arrived in Australia in October, but waited weeks for the surgery while they built up strength.

As Ms Zangmo wheeled her daughters out of the hospital, she paused to give thanks in English: "Thank you, everyone."

Feature Image: AAP