The Irish Cancer Society (ICS) is facing a 12% drop in income this year, while demand for its services continues to rise.
The society is appealing for public donations as it struggles to provide its night care and information services to patients and their families throughout the country.
Numbers of newly diagnosed cancers are increasing by up to 7% each year. The ICS has warned that without increased support, it may not be in a position to maintain service levels.
More than 7,000 people died from cancer in Ireland in 2007.