The social network, with its 550 million worldwide users, said it is "currently experiencing some site issues causing Facebook to be slow or unavailable for some users."
"We are working to resolve this issue as quickly as possible," according to a spokesperson.
The problems come at a somewhat inopportune time for the company, which is also dealing with the imminent release of "The Social Network," a movie that portrays founder and chief executive Mark Zuckerberg in a questionable (if fictionalized) light.