Children with life-long or chronic conditions will benefit from a redeveloped medical day unit and renal dialysis unit at Adelaide's Women's and Children's hospital.

The $4 million unit is part of an upgrade to the existing hospital while the planning and construction of a new facility is underway, Premier Steven Marshall said at the unveiling on Wednesday.

"We have committed to sustaining the current Women's and Children's Hospital while we plan and build a new world-class facility," Mr Marshall said.

"In the interim, chronically ill children will benefit from having access to a refreshed unit designed especially for their needs."

Shevahn Robinson visits the clinic at least once a week with her daughter, Elsie Glynn, who is hoping to receive a kidney transplant early next year.

Ms Robinson said the new facility will benefit both her and her three-and-a-half-year-old daughter, who has been receiving dialysis treatment for a year.

"It's nice to come into an area that's open, it's more comforting for them to come into a brighter space where it's not so dark," she said.

"It will make it more relaxing for me. It's hard enough at home with her sicknesses so it will be a lot more relaxing and calming to be able to come and sit down.

"Also for (the doctors) to provide better care as well, because they've got more room."

It is expected that 98 families will regularly use the unit, which has capacity for up to 18 different treatment spaces and will provide services including dialysis, allergy tests and intravenous infusions.