Wrapping up its annual meeting in the world's largest Catholic country, the National Conference of Brazilian Bishops also said it did not condone sending priests accused of abuse to other locations, a practice that has helped some alleged abusers escape prosecution.
The Associated Press recently reported 30 cases around the world of priests accused of abuse who were transferred or moved abroad, and some escaped police investigations. Many had access to children in other countries, and some abused again. The probe spanned 21 nations across six continents.
Conference president Archbishop Geraldo Lyrio Rocha called child abuse a sin for which the church must show "forgiveness and mercy," but also a crime that must be dealt with to the full extent of civil and canon law.
"Should a candidate for the priesthood show any sign that he may go down the wrong path in this area, he must be barred from entering the seminary," Rocha said.
A statement released by the bishops said clergymen accused of child abuse should be banned from the priesthood.
Sex abuse scandals involving the church have mushroomed around the world recently, and some of the accused priests have surfaced in Brazil.
Late last month, prosecutors charged the Rev. Jose Afonso with abusing altar boys ranging in ages from 12 to 16. Prosecutors said the alleged abuses took place this year, in 2009 and in 2001 in Franca, in Sao Paulo state.
Also last month, 83-year-old Monsignor Luiz Marques Barbosa was detained in northeastern Brazil for allegedly abusing at least three boys after being caught on videotape having sex with a young man, a former altar boy.
Barbosa is under house arrest while authorities investigate. Two other priests in the same archdiocese are also accused of abuses.
The bishops' conference announced earlier this week that it would prepare a manual with guidelines to help bishops combat child-abuse cases.
SIC: AP