Secured by a rope harness, the Rev. Tim Harrison climbed down from the cathedral's bell tower on Tuesday.
The priest had rappelled only once before - and that was during World War II, the Daily Telegraph newspaper reported.
Speaking of his most recent experience, he said, "All my life I have put my faith in Jesus Christ, but for the last ten minutes it has been with Mick upstairs," Harrison said, speaking of the representative from a local adventure sports company that set up the climb.
He later added, "It is a question of trust. You trust your gear and you trust your mate, and that also goes for life. I have had some good mates, and I have had some good gear."
The priest made the daring descent to highlight Seniors Week in the state of Western Australia. The week is meant to acknowledge seniors and highlight their contribution to the community.
Harrison, the cathedral's assistant priest, said the experience reminded him he still had a few good years left, the Telegraph reported.
"Driving around Australia gets a bit boring the third time round, so what are you going to do with yourself?" he said. "This reminds me I am still quite young - although I am a bit stiff. Maybe same time next year."Also Read