The Catholic Bishops' Drugs Initiative has warned St Patrick's Day revellers that starting to drink alcohol before the age of 15 makes you four times more likely to develop alcohol dependency later in life.
The group's vice-chair, Bishop Éamonn Walsh, has reminded parents research indicates that their influence on young people's drinking habits far outweighs pressure from peers.
The initiative operates in over 250 parishes throughout Ireland.
In a statement, it encourages individuals and families to celebrate the patron saint's national holiday without an over-reliance on alcohol.
Bishop Walsh said it is important that parents and other adults are aware of the consequences of under-age drinking so that they can reduce and prevent alcohol-related damage.
The initiative recommends never drinking and driving and having a fun day out either without alcohol or by drinking in moderation.