The bear dug into some food in a metal canister, which she dragged outside. Staff at the hospital called hunters, who arrived at the hospital, which is in a forest near the mountain resort of Predeal, 120 kilometers (75 miles) north of Bucharest.
"We shot her with a tranquilizer," said Aurel Iordache, one of the hunters.
Television footage broadcast by Realitatea TV showed the bear with her head stuck in the canister. She was seen waddling into the forest, woozy from the effects of the tranquilizer.
Romania is home to about half of Europe's brown bears. Three years ago, two men died after they were attacked by a rabid bear. In June a bear killed an American woman who was on honeymoon in Romania, and in July a man walking in a pasture in central Romania was mauled to death.