In a statement, Frank Coleman said he won't deny his beliefs, but he does not intend to force his personal views on others.
"It is with humility and honesty that I say unequivocally yes, I have as a private individual participated in the right to life walk held each Good Friday in Corner Brook," he said.
"I do not seek to impose my views on anyone and truly respect the gift of free will we are all afforded."
The issue arose after the CBC reported that Coleman's wife, along with some of their children and grandchildren, were spotted at the annual event outside the Western Memorial Regional Hospital.
Coleman was unavailable for an interview.
But his spokeswoman, Carmel Turpin, said Coleman did not attend the event because he was out of town.
Reaction came swiftly on Twitter, with a number of users condemning Coleman for his past participation.
"Saddened to hear today that our new premier @FrankColeman_PC is anti-choice. The sooner a @nlliberals government is elected the better," tweeted Kate White.
User Kayla Hayward asked what Coleman's stance on abortion would mean for the province down the road.
"Will NL (Newfoundland) end up like NB (New Brunswick), no abortion clinics funded?" she tweeted.
Coleman, a 60-year-old businessman, became the sole Progressive Conservative leadership contender Thursday after his only competitor dropped out of the race.
He has been endorsed by several cabinet ministers who chose not to run in a contest that drew just three contenders, all of them political outsiders.
A leadership convention is planned for July.