Around 13,000 people are attending the National Eucharistic Congress celebration in Knock, Co Mayo.
People have come from parishes all over the country.
The church is holding the event exactly one year ahead of an International Congress in 2012.
The Archbishop of Dublin, Dr Diarmuid Martin, said today's congress is part of a process of renewal.
Earlier this afternoon, the Sacrament of the sick was administered to hundreds of pilgrims both inside and outside the Basilica.