The men demanded to be allowed into the hospital, which was the scene of previous violence this week after a group of armed men started a mass brawl.
The nurse felt unable to stand up to the men and granted them access into the hospital.
“She dared not do anything other than let them in during a threatening situation,” police spokesperson Stefan Gustafsson at Gothenburg police told the TT news agency.
The police were called to the scene and duly searched the hospital but were unable to find the men involved.
The incident came only days after a gunfire erupted in connection with a brawl at the hospital.
Shots were fired at around 8pm on Wednesday evening as a group of six people armed with weapons began fighting in an apparent dispute between two families.
“We don’t know anything about whether this is connected to the week’s events, there is nothing which indicates that but we can’t rule it out,” Gustafsson said.
Three men are expected to be remanded into custody on Sunday in connection with Wednesday’s brawl.
Two men are set to be remanded on suspicion of aggravated assault and the other for attempted murder.