"Stressed" Maggie May had to be sedated after getting wedged between the stairlift and a rail at her home in Helsington in Kendal, Cumbria.
RSPCA Inspector Chris Towler did not want to dismantle the stairlift and leave the tabby's owners with no way of getting upstairs.
He eventually managed to ease Maggie May out using a jack to make a gap.
A check-up revealed she was totally unscathed.
"The cat had followed her owner down the stairs when she got caught under the lift," Insp Towler said.
"An engineer loosened the post from the rail but was unable to move the chair off of the cat as the floor bolts were covered by the seat.
"We talked about calling the fire brigade to assist with their cutting equipment but I wanted to avoid damaging the stairlift."
Insp Towler used a jack to push against the rail and adjacent wall, creating a gap enabling Maggie May to slide free.
He added: "The vet took her back to the surgery, and I was extremely pleased to hear that she suffered no injuries and was allowed to return to her very relieved owner."
A cat that got trapped in a stairlift has been rescued thanks to the dogged determination of an RSPCA inspector.