The fire _ which broke out in an area housing television and radio equipment, just below the tower's antenna _ was put out after about an hour, police said.
The cause of the fire was not immediately known, the company that operates the tower said.
The area where the blaze broke out is inaccessible to tourists, above the third floor observation deck _ the highest place visitors can reach, 910 feet up.
There are restaurants on the first two levels.
After black smoke began pouring from the tower's top at about 7:15 p.m., fire trucks and rescue vehicles gathered at the base as visitors streamed out.
A red helicopter swooped around the tower, appearing to inspect the lower floors. Police blocked off access as tourists waited on the grass below, taking photographs or peering up through binoculars.
The thick smoke began to taper off soon afterward. Just over an hour later, police said the blaze was extinguished.
Officials said they were not sure whether anyone was in the area where the fire erupted. There were no immediate reports of injuries.
The same portion of the tower caught fire in 1956, destroying the structure's summit.
The best-known monument in Europe, the iron-laced Eiffel Tower has had more than 200 million visitors since it opened at the Paris Exhibition in 1889. It draws 6 million visitors a year, making it the world's most popular paying tourist attraction.
