A woman who slipped on a greasy chip outside a Big W store in New South Wales has won a High Court battle for compensation from Woolworths.

Kathryn Strong suffered serious spinal injuries during the fall outside the store at Taree on the NSW mid-north coast.

At the time she had an amputated right leg and walked with the aid of crutches.

Around 12:30pm on the day of the accident, one of Ms Strong's crutches came into contact with the chip, leading to a heavy fall.

The chip was on the floor in a shopping area for which Woolworths was responsible.

The District Court initially awarded Ms Strong more than $580,000 in compensation.

But Woolworths won an appeal on the basis the accident happened at lunchtime, and it was very likely Ms Strong would still have fallen even if there had been dedicated cleaning every 15 minutes.

In a 4-1 judgment, the High Court has rejected that, saying on the balance of probabilities the fall was the result of Woolworths' negligence.

Ms Strong is now eligible for the original compensation.