The 115 French bishops, who meet in plenary session twice a year, fasted to mark the "too long guilty silence" of the church about paedophilia by priests.
It was their response to a call from Pope Francis in September to hold a worldwide day of "prayer and penitence" for victims.
Meetings about paedophilia have been organised in Lourdes and masses held across the country.
Several French church officials have recently been accused of failing to report paedophile priests to judicial authorities.
A scandal over Father Bernard Preynat, accused of abusing nearly 70 boy scouts, led to an investigation into Lyon Archbishop Philippe Barbarin for failure to report the suspicions, although the charges were eventually dropped.
In the wake of that case, alleged abuses were reported in Paris, Montauban, Toulouse, Clermont-Ferrand, Orleans, Bayonne and French Guyana.
In April the French bishops' conference announced a number of measures to respond to victims' complaints, including an email address that has received about 100 accusations of sexual abuse, many of them dating from before 1970.