Fifty non-emergency operations had to be cancelled at Leeds General Infirmary after a water leak led to a power cut.
The hospital has apologised to patients after the incident on Saturday evening.
Other hospital services continued to function normally.
David Berridge, deputy chief medical officer, said: “On Saturday evening some parts of Clarendon Wing at Leeds General Infirmary experienced a temporary break in the electrical power supply due to a water leak. “I can assure the public that there has been no impact on patient safety.
“Some medical equipment was affected by the temporary disruption in power but our essential equipment is protected by backup systems including reserve generators and battery packs.
“Until we can be assured that our electrical supply is stable we have put in place some contingency plans including postponing around 50 planned operations in that area of the hospital.
“We are continuing to carry out emergency operations and procedures.
“We apologise for any inconvenience this may cause but these measures have been put in place to ensure the highest possible patient safety.
“I’d like to thank all our staff for their tremendous efforts over the weekend to respond to this situation.
“All our other hospital services are operating normally.”