Daffodil Day is hoping to raise 3.4 million euro.
Last year was a wash out due to torrential rain and the charity says it's depending on strong support from the public today.
30,000 people are diagnosed with cancer in Ireland each year.
The money raised will go directly to fund the work of the Society across research, services and advocacy.
Hundreds of volunteers from Tipperary will be collecting across the county today.
