Municipal waste volumes fell by 8% in 2009, according to a new report.
The Environmental Protection Agency study states that Ireland is on course to achieving its EU waste objectives.
The decline in waste is most pronounced in the construction sector at 62%.
The findings contradict a 2009 report by the ESRI which predicted waste levels would grow by 4% a year until 2025.
That report was commissioned by Dublin City Council and was used to justify the controversial Poolbeg incinerator.
The EPA says the economic downturn has had a marked effect on our waste levels - particularly in the construction sector.
Its levels were down 62% in 2009, commercial waste was down 12% and household waste fell by 3%.
It says this is good news as it means we are on course to meet our targets set down by the EU on landfill diversion.
But the EPA is warning that tougher targets are likely to be put in place for the future and so Ireland needs to implement a number of measures including more source-segregated collections using three bins and further recovery of organic waste.