Visitors to the Paris landmark were all asked to leave at 1230 GMT after the unspecified alert, and the monument was reopened at 1430 GMT after police determined it was safe.
Security threats at Paris landmarks are common, although Friday's incident comes at a particularly sensitive time after the United States issued a global terror alert.
In March, The Local reported how a bomb threat, issued from the suburbs of the capital, closed down the landmark on a busy Saturday, causing 1,400 people to be evacuated.
And in June, a threat of a different kind shut down the 'Iron Lady,' when a Polish man in his 20s, perched on the second level of the tower, threatened to throw himself off.
He demanded the presences of cameras and news media, before police negotiators were able to dissuade him.
A bomb alert in April shut down another major landmark and tourist attraction, the Arc de Triomphe.
France has stepped up national security in the wake of its military intervention in Mali, which provoked various unspecified threats of revenge from Islamist extremist groups.