The famed reporter announced on his television program that he had fled to Costa Rica, without detailing the threats that prompted him to leave Nicaragua.
He said he planned to keep reporting from San Jose, where the government has welcomed him and his wife.
He told Reuters in late December that he had been targeted with death threats on social media and feared that the government could trump up charges as an excuse to throw him in jail. Chamorro said police had raided his offices earlier in December and taken his equipment, forcing him to work almost in hiding.
Nicaragua’s government did not respond to a request for comment. It has repeatedly said that freedom of expression exists in the country.
Chamorro, the son of former president Violeta Chamorro and a frequent critic of Ortega, runs the digital newspaper Confidencial and hosts television news programs.
His father, slain journalist and businessman Pedro Joaquín Chamorro, opposed right-wing dictator Anastasio Somoza in the late 1970s while at the helm of the newspaper La Prensa.
The younger Chamorro won an award from the Columbia University journalism school in 2010 for his coverage of Nicaragua.
Beginning in April, Nicaragua has experienced one of its worst crises since a 1980s civil war, with protests raging for months before being stifled by the government.
More than 300 people were killed in the protests, and more than 500 were incarcerated, according to the Nicaraguan Center for Human Rights. Dozens of journalists have been beaten and threatened, human rights groups say.