Dozens rallied in the East Flatbush section of Brooklyn on Monday to demand that Long Island College Hospital stay open, and they gathered outside of SUNY Downstate Medical Center, where a state university council meeting was taking place.
Unions have gone to court, accusing management of ignoring a judge's order to keep the hospital operational.
SUNY Downstate, which runs LICH, says the hospital is losing more than $1 million a week.
Supporters said the operators are being greedy.
"We believe it's a real estate grab. They're interested in the location for real estate for their own financial advancement and we're not going to tolerate that," said Sonya Thomas, a LICH registered nurse.
"They don't care about our health care system here. They just care about how much money they could put in their pockets," said community activist Burchell Marcus.
"The fact of the matter is that LICH has lost money for 17 straight years. It threatens the finances of the entire Downstate operation, which includes Brooklyn's only medical school," said Robert Bellafiore, a spokesman for SUNY Downstate.
Last month, the hospital moved critical care patients to other facilities.
Critics called it a scare tactic, saying the hospital is fully staffed and able to take care of patients.
They want Governor Andrew Cuomo to get involved.