Twenty five opposition supporters and journalists who could be sentenced to death or life imprisonment for attempted genocide and treason are acquitted and freed be the Ethiopian judge on Monday.
Federal High Court Judge Adil Ahmed said the prosecution had failed to prove the charges, which are part of a controversial trial against more than 100 opposition leaders, aid workers and union members.
"There is no evidence against them," the judge told the courtroom before acquitting eight journalists and 17 members of the main opposition party. He said the defendants, who have been in custody for 15 months, should be released immediately.
However the trial against other opposition leaders and aid workers will continue.
Among those freed was a female reporter who gave birth while in prison and editors and owners of opposition newspapers in the African nation.
The trial has been widely condemned by international human rights groups as an attempt to silence Ethiopian government critics.
It stems from the violence that erupted during protests over disputed elections that returned Prime Minister Meles Zenawi to power in May 2005.
Opposition leaders claimed that the vote was rigged and EU observers said the polls were marred by irregularities.
An independent Ethiopian investigation found 193 demonstrators and six policemen were killed in clashes between protesters and security forces that erupted after the vote, sparking a massive opposition crackdown.
Those who were released were not immediately available for comment.
The genocide charge is because the defendants are accused of targeting the Tigrayan ethnic group, from which the ruling party and Zenawi come. Tigrayans are from the north of the country and make up fewer than one in 10 of Ethiopia's 77 million people.
London-based human rights group Amnesty International has called the defendants "prisoners of conscience who have not used or advocated violence."
Zenawi has repeatedly stated that the opposition was trying to overthrow his government by force.