One of Victoria's most dangerous pedophile priests is behind bars, and he is unlikely to ever come out.

Predator Robert Patrick Claffey, 73, has been jailed for more than 18 years for using his position as a Catholic priest to sexually abuse 12 Victorian children between 1969 and 1992.

Victims drew parallels between Claffey and serial pedophile Gerald Francis Ridsdale, who abused more than 50 victims - one of whom was also attacked by Claffey.

In jailing Claffey, Victorian County Court Judge Felicty Hampel said the evidence revealed the culpable conduct of the Catholic church in the Diocese of Ballarat, and more broadly.

From 1969 to the mid-1980s, Claffey attacked children as young as five, unchecked, until the father of one of his victims reported the priest to the Bishop of Ballarat, Ronald Mulkearns.

Bishop Mulkearns has since admitted not dealing with pedophile priests properly, saying he was trying to protect the church's reputation and stop further offending.

He knew Ridsdale and others were sexually abusing children and moved them between parishes.

After serving a period of suspension, Claffey again offended in 1992.

The 19 charges Claffey admitted constitute what Judge Hampel called a shameful and protracted abuse of his authority as a priest.

He started by abusing a seven-year-old girl.

One year after he was ordained, Claffey took a schoolgirl into a storeroom and forced himself on her, telling her it would "kill" her mother if she said anything.

Five years later in Warnambool he indecently assaulted a 13-year-old boy in his bedroom.

Claffey had developed a habit of dropping in on the boy's family home and it was this type of behaviour, Judge Hampel said, that constituted the "grooming" of parents which enabled him to act with impunity for so many years.

He repeated the pattern in 1977 with another boy, who fought him off with a cricket bat, but not before an act of indecent assault was committed.

Another victim he attacked in a school shed and yet another - an alter boy - in a church vestry before mass.

"You would touch (the victim) ... then make casual conversation before you yourself robed and went onto the alter to say mass," Judge Hampel said.

"He was too scared to move."

One of his victims said the sentence for the "unbridled and unbroken rape" of the children of western Victoria was just, fair and tantamount to a death penalty.

"Bob Claffey has taken a fair portion of everyone's lives and he deserves to have a fair portion of his life taken from him," Frank Hampster said outside court.

Another of his victims said she suspected there were others out there.

The remorseless child abuser has offered no apology.

Claffey's total sentence is 18 years and four months, of which he must serve 13 years and four months.