The skeleton of the fossilised, 3.2 million-year-old human ancestor known as Lucy, will go on display in the US, Ethiopian officials say.
After four years of negotiations with the Houston Museum of Natural Science in Texas, Ethiopia agreed to lend the bones for scientific study until 2013.
It is hoped Lucy's 11-leg tour will boost tourism and increase Ethiopia's profile as the "home of all humanity".
She will leave her country of origin - and the origin of mankind - in June.
As well as Lucy, the travelling exhibition will also include about 190 other Ethiopian artefacts including humankind's earliest stone tools.
Officials say money from the tour will be used to improve museums across the country.
After Houston, Lucy's skeleton will be put on display in Washington, New York, Denver and Chicago. Six other city destinations have yet to be confirmed.
Ethiopia's minister for culture and tourism, Mahmoud Driri told the BBC that the discovery of Lucy represented "the true story of Ethiopia being the cradle of human civilisation and the home of all humanity.
Lucy's remains were found in 1974 in Hadar, Ethiopia
"She will be the only mute ambassador that can talk more than any other ambassador for the time being," he added.
Mr Driri said he hoped that a million tourists would visit Ethiopia within five years and that African Americans would look upon Ethiopia as their spiritual home.
"The bottom line is to make Ethiopia one of the 10 most important African venues," he said.
Lucy was discovered in Hadar, Ethiopia, in 1974 by a team of palaeoanthropologists who were fans of the Beatles' song Lucy in the Sky with Diamonds.
For more than 20 years it was the oldest human ancestor known to science.