They include a number of sinister-looking pictures (which are definitely not of hubcaps or Frisbees) and detailed reports of sightings all over the world.
You can view them all at CIA.gov or click this link.
Despite the internet going into complete meltdown over the news, there are sadly no documents about close encounters with little green men, or what the US government's really doing at Area 51 (hint: it doesn't involve alien autopsies).
Writing on its website, the CIA said: "We've decided to highlight a few documents both skeptics and believers will find interesting."
One report says: "Less than 100 reasonably credible reports remain 'unexplainable' at this time. It is recommended that CIA surveillance be continued.
"It is strongly urged, however, that no reports of CIA interest or concern reach the press or public."
Source: Cornish Guardian UK