Pope Francis lifted the Vatican's secrecy rule for sexual abuse cases on Tuesday in response to criticism that the "pontifical secret" has protected paedophiles.
Sexual abuse cases have rocked the Catholic Church for decades and the new decree will allow authorities to gain access to case materials and victims to view documents.
"The person who files the report, the person who alleges to have been harmed and the witnesses shall not be bound by any obligation of silence with regard to matters involving the case," the new Vatican decree states.
But it specifies that though cases will not be protected under the highest "pontifical secret", they will be "treated in such a way as to ensure its security, integrity and confidentiality".
Many have said the new law is long overdue. The subject came up at a Vatican summit that took place last February.
"Children are more protected when information about abusers is made public," said Zach Hiner, executive director of the Survivors Network of those Abused by Priests in the US.
"This has all come about from public pressure," he explained, stating that the Church needed to catch up to others' efforts.
Back in 2001, the Vatican said that the measure protected victims, which critics say is incorrect.
Still, survivors welcomed the decision of Pope Francis.
"Today is an important day in transparency and justice for victims," Juan Carlos Cruz, a Chilean activist and survivor of sexual abuse tweeted.
The Vatican law also changed the definition of what it considers child pornography raising the age of a minor to anyone under 18.
The decree was issued on Pope Francis' 83rd birthday.
Watch the report in the video player above.