Up to 20,000 pilgrims are to gather at Knock Shrine in Co. Mayo next month to celebrate a national Eucharistic Congress.
The June 25-26 event is being seen as a key moment of preparation for next year's International Eucharistic Congress that will be held in Dublin.
Pilgrims are expected to travel from every diocese in Ireland on Saturday June 25 with corresponding local events taking place the following day, Corpus Christi.
According to Fr Kevin Doran, secretary general of the 2012 event, the Knock congress will be ''one of the biggest gatherings since the visit of Pope John Paul [to Knock] II in 1979''.
Fr Doran says: ''The National Eucharistic Congress at Knock will only be a small taste of the kind of thing that we can expect at the International Congress in Dublin next year.''
The celebration of the Eucharist will be the central focus of the day with almost every Irish bishop participating and 26 large candles will be blessed for each of the Irish dioceses.
According to Fr Doran, ''these candles, as symbols of our communion with Christ and with one another, will be brought back to each diocese to be placed at the centre of a diocesan celebration on June 26.
''They will become a reminder of Christ's presence in each diocesan community and of the communion of the Irish Church,'' he said.
The 2012 Eucharistic Congress - which will be held in Dublin from June 10-17 - is expected to draw tens of thousands of pilgrims from Ireland as well as overseas and is being seen by the Church as a key moment of renewal and focus on the Eucharist.
The theme of the congress is 'Communion with Christ and One Another' and local events are planned in parishes and dioceses across the country to prepare parishioners for the event.
It is not yet clear whether or not Pope Benedict XVI will travel to Ireland to participate in any of the events.