The Colombian government and the Farc rebel group have agreed to set up a memory commission to investigate the deaths of thousands of people in five decades of conflict.
They have agreed to hear the demands of victims, who will travel to Cuba, where the peace talks are taking place.
The announcement is being seen as a significant step towards peace.
Some 220,000 people, many of them civilians, are estimated to have died in the conflict.
"The rights of the victims are non-negotiable," says a statement released in Havana.
The document lays out 10 points that will be the basis for discussions in the next round of talks, focusing on the victims of the conflict.
It says that the "victims must be recognised not only in their position as victims, but as citizens with rights".
The "victims of human rights abuses" have the right to the truth, justice, compensation and the guarantee that such violations will never happen again, says the document.
Victims of the conflict and their relatives will go to Havana, apparently in the near future, to share their experiences.
The acknowledgment by the guerrillas that there were victims in the conflict has been seen in Colombia as a historic statement, says the BBC's Arturo Wallace in Bogota.
The left-wing rebels and the government have so far rejected allegations of human rights abuses and blamed each other for the deaths and the displacement of at least 3 million people.
"Today is a special day. The day of the victims has arrived. We have made a huge step. The Havana process is not simply a closed door conversation about clashes," said government negotiator Humberto de la Calle.
"Each day we feel closer to the mountaintop, to the Mount Everest of rights, which is peace. Without that no other rights are possible," said rebel negotiator Ivan Marquez.
Peace and impunity
The peace process launched by President Juan Manuel Santos in November 2012 is one of the most controversial issues in the debate ahead of Sunday's presidential election.
Mr Santos has vowed to carry on negotiating with the left-wing rebels if he is elected to a second term.
His rival in the run-off vote, right-wing candidate Oscar Ivan Zuluaga, initially said he was willing to put an end to the talks.
But he is now saying that the government would proceed with the negotiations provided the Farc accepted tougher conditions.
There will be no "peace with impunity," said Mr Zuluaga.
The presidential election has become for many a referendum on the validity of the peace process, says our correspondent.
There has been agreement on three of the six points in the agenda being negotiated in Cuba: land reform, political participation and illicit drugs.
The talks now enter a new phase with the debate on the rights of the victims.