Almost 93 surgeries were cancelled each day during the month of January, according to Sinn Féin.
The party also says hospitals across the country currently face up to 100% occupancy each week.
They say that patients' health is being severely undermined by underinvestment in the Public Health Service.
Sinn Féin Health Spokesperson Louise O'Reilly says the cancelling of surgeries is adding to the Emergency Department crisis.
Ms O'Reilly said: "People who are in pain and who need surgery are being sent back whom or being told not to come into hospital, but what happens to those people is they get so desperate they enter the hospital via the only door that is open to them, that's Accident and Emergency.
"We now see that these figures are climbing high and not getting any lower.
"Part of that has to do with the pressure that's being put on by cancelled surgeries, people get desperate."