Fifteen monks were found guilty of sexual abuse at a monastery in Einsiedeln, in central Switzerland, in cases stretching back over six decades, an investigative panel said on Thursday.
The panel said there were at least 40 victims, with the majority of the cases occurring in the 1960s and 1970s.
The cases only began to come to light when preventive measures were introduced in 1998.
Nine of the monks found guilty committed indecent acts on children, the panel said.
Three monks were found to be ring leaders and the notion of sexual abuse at the monastery had become accepted, the investigators said.
For the first time last year, the Catholic Church in Switzerland compiled detailed statistics of cases of sexual abuse committed by priests and other pastoral workers.