A government decree said all military and civilian pilots as well as air traffic controllers should register any UFO sightings with the national aerospace defense command.
The information will be stored in the national archives in Rio de Janeiro.
It will be made available to researchers, including those seeking evidence of extraterrestrial life.
Anything unusual that is seen, photographed or video filmed in Brazil's air space will now have to be reported and cataloged.
But the air force said it would limit itself to collecting information, and would not be chasing UFOs.
"Air force command does not have a specialized structure to carry out scientific experiments on these phenomena and will limit itself to recording any events" the air force said in a statement.
Out there somewhere?
There have been several reports of UFOs in Brazil in recent decades.
In 1986, air force jets were scrambled to investigate unidentified objects in the skies above Sao Paulo, but the phenomenon was never fully explained.
And in 1977 the Amazon town of Vigia asked for military help after some residents said they had been attacked by extra-terrestrials.
One anonymous air traffic controller told the Brazilian newspaper O Dia that sightings had been reported at the highest level."I have heard of ministers and even a president who said they had seen a UFO", he said Rate this posting: