The reception came despite warnings from security forces that large gatherings of people were illegal in Egypt and that crowds could be dispersed.
Up to 700 people gathered at Cairo's airport to wave banners and offer chants of support for ElBaradei, the BBC reported.
Thousands of ElBaradei supporters were not allowed past checkpoints near the airport, the report said.
ElBaradei is considered to be a possible presidential candidate in Egypt's 2011 election, athough, in January, he said he wouldn't run.
There has been speculation that Egyptian President Hosni Mubarak is preparing his son Gamal to serve as his successor.
ElBaradei, 57, was awarded the Nobel Peace Prize in 2005.