There was a single fire at Royal Cornwall Hospitals in the last year, new figures show.
The Liberal Democrats – who collated the information – warned buildings across the NHS in England “are in a very bad way and getting worse”.
The political party sent freedom of information requests to every hospital in the country.
The 84 that responded – around 41% – reported 290 fires between mid-2022 and summer of this year.
This included one at Royal Cornwall Hospitals NHS Trust.
Across England, these trusts also reported 337 broken fire alarms and more than 4,000 false fire alarms.
Royal Cornwall Hospitals had 17 out-of-service fire alarms over the past year, and 162 false alarms were made over the same period.
Liberal Democrat health and social care spokesperson Daisy Cooper MP called the findings "shocking".
She said: “Hospitals are falling apart, with chemical leaks in critical wards and a frightening number of faulty fire alarms. The repair budget for crumbling hospitals is mounting up yet ministers are nowhere to be found.
“Patients deserve the dignity of being treated in safe, modern and clean hospitals. Instead we have heard stories of sewage spills and chemical leaks leading to evacuations. The British public pay their fair share and deserve better than this."
Separate figures – also compiled by the Liberal Democrats – show 115 chemical leaks over this period across 70 hospitals, although Royal Cornwall Hospitals did not provide information on their hospital.
Last month the public spending watchdog said the Government is on track to break a key promise to build 40 new hospitals by 2030.
A report by the National Audit Office found delays in projects mean the target is not likely to be met.
By the watchdog’s analysis, 32 hospitals in England defined as 'new' by the standards the Government first used are set to be completed in 2030.
A Department of Health and Social Care spokesperson said: “Patient safety is our top priority and we are investing record sums to upgrade and modernise NHS buildings so staff have the facilities needed to provide world-class care.
“This includes £4.2 billion last year and a further £8.4 billion over the next two years to allow trusts to invest, refurbish and maintain their buildings.
“We are also building 40 new hospitals by 2030 through the New Hospital Programme, which is now expected to be backed by over £20 billion.”