Two wards at the Royal Berkshire Hospital in Reading had to be evacuated on Sunday after they were flooded when a water pipe burst.
About 50 patients had to be moved to other wards after the area they were in became water logged.
It happened at about 1900 GMT, a hospital spokesperson said.
Up to 25 firefighters were called to the hospital and it took them about two and half hours to stop the leak and clear away the water.
The affected patients were not in intensive care and could be moved without difficulty, the hospital said.
A full assessment of the damage will now be done.