NHS Greater and Glasgow Clyde has been forced to axe 324 planned procedures – 10% of the total figure – since Monday as a result of the winter vomiting bug.
The health board said the severe outbreak had put "pressure on our services".
They also said an "unprecedented increase" of people being admitted through A&E departments compared with the same period last year had exasperated medical teams.
However, the board has come under fire from a patients' group, which says a contingency plan should have been in place to cope with the virus.
Jane Grant, chief operating officer for acute hospitals, said: "While we have done everything that we can to avoid having to postpone planned procedures we have unfortunately had to postpone around 10% of our planned elective procedures so far this week.
"In doing so we have prioritised clinically urgent planned surgery."
This week four NHSGCC staff members were reported to have the virus.
Neighbouring health board NHS Lanarkshire has seen 24 staff members struck down by the illness in the past month.
A spokeswoman from the health board said no operations had been affected.
It came as figures published by Health Protection Scotland revealed around one in five Scots has picked up the bug, which causes vomiting, stomach cramps, fever and diarrhoea.
It has caused havoc to work places across the country, resulting in hospital ward closures.
Jean Turner, from Scotland Patients' Association, urged medical staff to work over weekends to tackle the back log of operations.
She said: "There obviously isn't enough staff to carry out procedures but that has a lot to do with workforce planning.
"I just hope when it is over that staff work weekends so that operations can be cleared quicker and that they don't turn to the private sector to clear up the mess."
Ms Turner added that cancelling procedures could be "very disturbing for the patient".
She said: "Patients may have had to take time off work or their families may have planned to come and stay with them."
Ms Grant said medical staff were doing as much as they could to make sure services ran smoothly.
She said: "Credit must be given to our staff who continue, as ever, to rise to the challenge of the busy winter period."
She said day case and out patient services had been "running as normal".
It came as NHS Tayside revealed they turned away 40 patients due to go under the knife this week.
Lesley McLay, NHS Tayside's chief operating officer, said: "Unfortunately, the decision has had to be taken to cancel non-urgent routine elective surgery for Tuesday and Wednesday this week."