Representatives of a half-dozen Catholic reform groups marched on St. Peter's Square on the eve of a three-day rally marking the end of the church's yearlong celebration of the priest.
Vatican officials have said during the rally Pope Benedict XVI may apologize for the decades of rapes and molestation that children suffered at the hands of priests.
The umbrella group Women's Ordination Conference said the Vatican shouldn't be celebrating the priesthood while "turning a blind eye when men in its ranks destroy the lives of children and families."
"While the hierarchy spends their time covering up scandals and throwing major celebrations for themselves, Catholic women are working for justice and making a positive difference in the world," said Erin Saiz Hanna, the Women's Ordination Conference executive director.
She spoke at a news conference before a dozen members of the reform groups marched to the Vatican in a bid to hand out flyers to tourists, priests and other passers-by.
Police stopped them when they reached the square and asked them to leave, which they did.