First they failed to spot that little Courtney Blake had broken her leg at all and she was left untreated for five days.
Then the hospital put the wrong leg in plaster.
Courtney's mother Kelly Ann said she was appalled by the treatment her daughter received at Doncaster Royal Infirmary, in South Yorkshire.
"I'm totally disgusted. I just can't believe they let a three year old go through that. Courtney was very distressed and frightened and was wondering what was going on," she said.
Ms Blake said that Courtney was first taken to the hospital last Friday when she fell down several flights of stairs at their home in Rossington.
At first the family thought Courtney was merely in shock after the fall, but when she continuously complained of pain they took her to accident and emergency for an X-ray.
Ms Blake said no-one examined her daughter and said the X-rays showed a sprain rather than a break.
"When we finally got in to see the doctor he didn't even touch her leg or examine it. He just looked with his eyes and said he would send her for an X-ray.
"We got the pictures back, he called us in and said it wasn't broken but was probably sprained," she said.
Wrong leg
They bandaged the leg and sent her home, but after complaining for a week of pains in her legs Ms Blake took Courtney back to the hospital.
A senior registrar re-examined the X-rays found the break and called for her leg to be put in plaster.
But when Ms Blake got Courtney home she discovered that they'd put the wrong leg in plaster.
A spokesman for the hospital said that they had launched an investigation into what had happened to Courtney and that they were keeping the family up to date.
"We can't comment on this case particularly, but in general terms, it's not always possible to see a child's fractures in X-ray because the bones are still developing and are relatively soft," he said.
But he added that the hospital had made an apology over their blunder over putting the wrong leg in plaster.
"On the issue of plaster, clearly a mistake was made and staff have visited the family this week to apologise for any distress that was caused," he said.