The 16-year-old macaque monkey escaped June 28, Winston-Salem (N.C.) Journal reported.
There was a sighting of the monkey Friday, said Chad Campbell, a spokesman for Wake Forest Baptist Medical Center.
"We responded, but unfortunately it didn't result" in another sighting or recapture, Campbell said.
Campbell said Wake Forest officials are now using a recording of a baby macaque to try and lure the adult monkey in, in addition to personnel searching areas the monkey has been spotted in and the placement of humane traps in those areas.
The monkey, which is about the size of a house cat, is used for breeding and research purposes at the primate center, the newspaper reported.
Tim Jennings, the director of Forsyth County Animal Control, warned local residents against trying to handle the monkey, as it is not tame and could bite or scratch anyone who tries to approach it.
"The monkey is not generally considered to be any more dangerous than a raccoon, but it is wild, so you certainly don't want to handle it," Jennings said.