Morales on Monday announced he plans to take over the SABSA airports serving Bolivia's three largest cities.
Morales, who made the announcement at a news conference in the city of Cochabamba, promised negotiations with SABSA, an affiliate of the Spanish firms Abertis and Aena, within 180 days on the amount of compensation.
He also ordered the military to take control of the three airports "to safeguard the public interest" and warned that any attempt to impede the nationalization would mean prosecution for those involved.
The company has run the airports serving La Paz, Cochabamba and Santa Cruz since 1997, when they were privatized. It was acquired by the Spanish group Abertis-Airports in 2005.
It is the third nationalization affecting Spanish investments in Bolivia in less than a year.