A third ward at Victoria Hospital in Kirkcaldy has been affected by an outbreak of norovirus.
Ward 43 has been forced to close after a number of patients contracted the virus, which is often referred to as the winter vomiting bug.
Ward 12, which closed last week, remains shut although Ward 10, which was also affected last week, has now re-opened.
A spokesman for NHS Fife said that wards 12 and 43 were expected to reopen early next week, following a deep-clean.
NHS Fife medical director Dr Frances Elliot said: “The reason that these wards have been closed is to prevent the spread of norovirus. This has been done as a precautionary measure and all infection control measures have been put in place.
“I would once again take this opportunity to remind members of the public not to visit relatives in hospital if they are feeling unwell, especially if they are suffering from the vomiting and diarrhoea associated with norovirus.”
Norovirus is the most common stomach bug in the UK and can last between 12 and 48 hours.
It can affect people of all ages and causes vomiting and diarrhoea and, as there is no specific cure, patients have to let it run its course.
Most patients make a full recovery within two days without having to see their GP.