Father Finian Egan had escaped punishment for sexually abusing young girls for more than 50 years.

But now the frail and elderly Catholic priest has been jailed for at least four years for abusing three young NSW girls over the course of three decades.

Egan's victims, whose lives were irrevocably damaged by the abuse inflicted on them, stood in the District Court in Sydney on Friday and watched as he was falteringly led away to spend his first night in jail.

He will be 83 years of age by the time he is eligible for release.

Egan enjoyed a position of power and privilege as a Catholic priest at a time when, among religious communities, priests were considered among the elite of society.

He abused that position of power again and again, preying on vulnerable young girls whose "powerlessness and helplessness" was exacerbated by their vulnerability, Judge Robyn Tupman said as she sentenced Egan to a maximum term of eight years.

His first victim was just 10 years old when her family sent her to a Sydney disadvantaged girls' home in 1961, in the hope she would receive better care than they could give her.

"Her troubled family asked for protection from the church but did not receive it," Judge Tupman said.

Instead the girl was targeted by Egan, then aged 27, who regularly invited her to the church sacristy where he pulled her on his lap and indecently assaulted her.

He said her hair was beautiful, prompting her to ask for it to be cut off in the hope that he would then no longer be interested in her.

To this day, the woman hates being complimented or having her hair touched.

She described how she kept the abuse secret for 50 years after initially confiding in a nun who then flogged her, forced her to drink castor oil and made her clean up her own vomit.

"It's unfortunate in the extreme her complaint was not taken seriously by those whose care she was under, because it might have meant the other (victims) in this trial were spared the sexual attention of the offender," Judge Tupman said.

Instead, Egan was free to strike again a decade later when he victimised a 17-year-old girl whose family he befriended.

The devout Catholic family thought Egan, their parish priest, was "charming and charismatic".

But he abused his victim - "a naive good Catholic girl" - in front of her unsuspecting mother before raping her in a convent.

Afterwards, he took her to confess her "sins" to another priest who ordered her not to let Egan touch her again.

She tried to jump out of Egan's moving car immediately afterwards.

The woman wept as Judge Tupman said Egan's abuse "took away her childhood and innocence".

Egan's third victim, Kellie Roche, refuses to be labelled as such.

"I'm a survivor," she told the court.

When Egan inappropriately touched her in 1987, she confided in her religious mother who refused to believe her and labelled her claims as "rubbish".

The priest went on to indecently assault Ms Roche, then aged 17, in a playground.

Egan, who was found guilty of rape and seven counts of indecent assault by a jury last month, has never shown remorse.

"He thinks he hasn't done anything wrong, still," Ms Roche told reporters outside court.

"(But) someone who is a danger to society is now off the streets."

Egan will be eligible for parole in December 2017.