Allegations of abuse have been made against 42 priests in the diocese of Down and Connor in the past 38 years, an audit has revealed.
It revealed that since 1975, 59 allegations had been made in the diocese.
Three priests have been convicted of offences against children.
The report went on to say that 14 allegations since the appointment of Bishop Noel Treanor five years ago had been properly managed.
In seven of these cases, there was insufficient evidence to proceed.
"All of these seven priests are in good standing in the diocese," the report said.
The report found that the diocese, which covers most of counties Antrim and Down and is the second largest by population on the island of Ireland, complied fully with 46 of 48 criteria.
The review was carried out in May this year.
Its report said: "This is an excellent result and indicates the very successful and effective investment of time and resources by the Diocese of Down and Connor in its child safeguarding services over the last five years."
The two outstanding criteria referred to support for and monitoring of priests who have abused and a written plan of action on implementing and monitoring standards.
Bishop of Down and Connor Noel Treanor said his thoughts and prayers were firstly with victims of child abuse and their families.
"They have experienced much suffering and pain and the church will always bear this wound.
"I pledge to continue to put all resources in place to help and support victims.
"As I have in the past, I offer my unreserved apology for the pain of child abuse carried out by some clergy within this diocese and for the failure of the church when dealing with those so wrongfully hurt."
He added: "This review confirms that when people come forward today that they will be listened to and action will be taken promptly in conjunction with the relevant statutory authorities.
"Sadly for survivors, this improvement has come far too late."
The watchdog published audits of six of its dioceses and two religious orders on Tuesday.
It scrutinised both current practice when dealing with abuse allegations and the handling of all allegations received since January 1975.
In the Armagh Archdiocese, run by Cardinal Sean Brady, the audit said that it found little information on the receipt and management of allegations before 1995.
It said there was "inconsistent filing leading to a lack of clarity about how decisions were made".
The report found Cardinal Brady, on taking up his role as Primate of All-Ireland in 1996, made a "commendable decision to gather and document whatever information was available.
"However, the reviewers cannot be confident that the records of allegations made prior to 1995 are complete. The reviewers looked at a small sample of documentation from this period."
Sixteen priests in the archdiocese have faced 36 allegations and four of them are still in ministry, the audit found.
Only one priest has been convicted and the audit said no allegations have been made since 2000.
Cardinal Brady said: "While we acknowledge the report's findings that in the past the response was not as prompt, robust and coordinated as in the present, we will continue to do all we can to ensure that current high standards of safeguarding practice are maintained."