The animal charity is revisiting unsolved cases, asking for public help in tracking down those responsible for a string of animal cruelty crimes.
The five-week-old kitten was found by a member of the public in a box in a field, hidden beneath conifers in Doncaster in January.
She was soaking wet and had a serious injury to her back leg.
RSPCA animal rescuer Katie Hetherington rushed the kitten - named Hattie - to the vets for urgent treatment.
She said: “This poor kitten was found in a box with a severe fracture to her leg which saw her leg almost hanging off.
"She must have been in a lot of pain, scared and confused when she was dumped like rubbish and left in a field.
“The kitten was clearly in need of urgent veterinary treatment and it is totally unacceptable to abandon an animal, especially in this state.”
Hattie had to have her leg amputated and was taken to RSPCA Doncaster and Rotherham branch to recover and recuperate.
She’s since been rehomed and is settling in well with her new family.
But the investigation remains open.
Katie Hetherington said: "This was a shocking incident which saw a kitten in need of urgent veterinary care being callously abandoned.
"Poor Hattie had suffered a painful fracture which resulted in her leg needing to be amputated but thankfully she has recovered well and is adapting to life on three legs."
Call the RSPCA on 0300 123 8018 with information.