The 15 kitchens in Leicestershire are the latest to be publicly criticised for their poor hygiene after inspectors found mouse droppings, dirty floors and walls, and incorrectly stored and heated food.
School kitchens in several other areas of England have also been named and shamed over the past two years, partly as a result of council reports and partly because of investigations by local newspapers making use of freedom of information legislation.
In Leicestershire, the problems came to light after routine inspections and have triggered a "rigorous hygiene regime" in all 240 of the county's schools, with training sessions and a new food safety policy.
Mouse droppings were found in the dining area of St Joseph's Primary in Netherhall, as well as behind a freezer. They were also found in a kitchen cupboard at Alderman Richard Hallam Primary in Beaumont Leys.
One of the dirtiest kitchens was found at South Charnwood High School in Markfield, where caretakers were allowed to make tea in the kitchen while wearing the same clothes they wore for cleaning drains and toilets. The kitchen wall was also mouldy, with sandwiches and fruit salad kept under heat lamps, which would support the growth of food poisoning. A thorough "deep clean" was needed, inspectors said.
A council spokesman said action to bring the 15 kitchens up to standard had either been carried out or was scheduled.
"Each kitchen will be visited on a weekly basis," he said.
Similar problems have been found in school kitchens in other areas of England.
Earlier this year, an information request by the Newcastle Journal revealed that mouse droppings, dirt and flies had been found in some school kitchens in the North East. Menus falsely claiming that food was organic, home made or low fat were also found.
Similar investigations by other local newspapers last year found 43 schools in Hampshire with poor and unhygienic kitchens, 56 in Worcestershire and 17 at Mansfield in Nottinghamshire.