Thousands of people around the country began a 24-hour fast this morning in the hope of raising funds for Concern.
Concern has been running the fasts annually for the past 36 years.
This year, it hopes to raise €2 million for projects in 30 different countries where they are providing emergency supplies and support for impoverished and famine-stricken communities.
The charity says it was able to train 4,700 teachers from the proceeds of last year's fast, bringing education and hope to tens of thousands of children.
A further 1.5 million people benefited from Concern's Livelihood programmes, which provided seeds, tools and funding for irrigation schemes to enable rural communities to fend for themselves.
"The fast is an integral part of our fundraising campaign," said Concern chief executive Tom Arnold. "Each year we can see improvements in communities by being able to provide long-term sustainable programmes through training in education, health, waste management, infrastructure and agriculture."
In addition, he said, Concern spent €5.8 million in the past month on relief packages for 20,000 families left homeless by the earthquake in Pakistan.
"None of this would be possible without the tremendous funds we receive from the annual 24-hour fast."