The Rev. Alejandro Solalinde, who is known for his work with Central American migrants, was released after a four-day stay at a hospital in the southern Mexican state of Oaxaca, hospital spokesmen said.
Solalinde was released on Monday "after showing improvement in his health," but "he must rest," spokesmen for Macedonio Benitez Community Hospital in the city of Juchitan said.
The human rights activist was hospitalized last Thursday with a high fever and body aches.
Some media outlets speculated that the Catholic priest might have contracted dengue.
Solalinde underwent a series of tests and was treated "in time," hospital spokesmen said, without providing details on the illness.
The priest, who founded the Hermanos del Camino shelter in 2007 to help Central American migrants, did not speak with reporters.
Solalinde returned to Mexico recently and is being protected by Attorney General's Office agents.
The human rights activist was forced to leave the country after getting death threats and learning in April that he had a price on his head. EFE