The Pioneer Total Abstinence Association (PTAA) faces imminent closure unless it can raise new funds, according to its chief executive.
The organisation, founded in 1898 by Jesuit priest Fr James Cullen and characterised by its 'pioneer pin' is projecting a deficit of €100,000 for 2011.
At its height, the organisation promoting temperance had 360,000 members. Today it claims between 125,000 and 150,000.
In an open letter to members posted on its website, chief executive Padraig Brady said the deficit had arisen from the decline in the Pioneer magazine circulation and other income sources.
He said the organisation had now reached "crisis point" and needed an "urgent injection" of funds.
"Sadly it is in these times of crisis and uncertainty that people turn to alcohol and drug abuse to escape the unbearable reality of living. Our appeal is as much for these people and their families as it is for our valued members and our association," he writes.
"As Pioneers we are known the length and breath of Ireland for our tradition of giving to others. The time is well overdue for us now to give to ourselves. Our failure to do so may have potentially dire consequences for as an organisation and for the innumerable individuals and families to whom we offer help."
Mr Brady appealed to members to donate at least €10 in order to keep the organisation afloat.
It is hoped that the appeal will raise the €300,000 needed to avert closure.
Mr Brady admitted to the Irish Catholic newspaper this week that his organisation "had failed to move with the times and put our message in modern language".
However, he said, the organisation was "first and foremost a movement based on prayer" and that there was "quite a bit of feeling that we should concentrate on this rather than trying to be things that we are not.