The company was hauled before the courts in December after Woolworths Dunedin South (formerly Countdown) was closed for 18 days in February 2024, following numerous sightings and captures of rodents.
Twenty-three rats were caught while it was closed.
It admitted a charge of breaching the Food Act, which carries a maximum fine of $200,000.
Yesterday, the court heard that between October 2023 and February 2024, at the Dunedin South store, rat sightings were reported to management, recorded in the relevant register and a pest control contractor attended.
But the company deviated from their food safety plan when it failed to escalate the situation by notifying the food safety team.
This only happened on January 9, 2024.
Between October and December there were approximately 112 rat sightings logged in the register.
A rat had chewed through wires of a forklift, the summary of facts noted.
Counsel for the Ministry for Primary Industries Leonie Matehaere said, this was not a case where the rats were going undetected - staff were reporting sightings of the rodents and wanted more to be done.
Counsel for Woolworths Joe Edwards put the issue down to a "systemic failure" within the store which the company apologised for.
Since the infestation, the company had analysed all operating procedures, training and policies and got them to a "gold standard", he said.
Judge David Robinson said the initial response to the infestation was "ineffective", but Woolworths "got there eventually".
"It appears that the lack of escalation can be traced back to a lack of understanding as to who bore the responsibility to escalate the issue," the judge said.
While there was no evidence of illness caused by the rats in the aisles, staff and customers were exposed to risk, the judge said.
"The company’s failures had potential to expose customers… to potentially serious illnesses," he said.
He accepted the company had admitted its wrongdoings promptly and noted the work it had since been "striving toward the gold standard".
Judge Robinson fined Woolworths $33,000.
