The charges were brought by the Ministry for Primary Industries after an investigation.
Counsel for MPI said the company faced a penalty of about $50,000-$55,000.
At the time the charge was laid, New Zealand Food Safety deputy director-general Vincent Arbuckle said Woolworths had failed to ensure a significant rodent infestation was promptly identified and escalated in accordance with its food control plan.
Woolworths NZ is due to be sentenced in March next year.
– RNZ