Droppings were found during store inspections, the court heard
Tesco has been ordered to pay £74,000 in fines and costs after mice were seen between the aisles of a Suffolk store.
Suffolk Coastal District Council said its food safety team found a "catalogue of problems" at Tesco Extra in Martlesham, near Ipswich.
Tesco was convicted of eight hygiene-related offences from April to August 2007 following a trial on Monday.
Magistrates in Ipswich fined the store £17,000 and ordered it to pay £57,000 towards the council's costs.
Poor cleaning and inadequate procedures had meant that parts of the store had become dirty and mice were active in many areas, the council said.
Members of the public reported seeing the rodents running between the aisles.
The eight offences under Food Hygiene regulations included failing to ensure adequate procedures were in place to control pests at a food premises and failing to ensure the food premises was kept clean.