Figures from the Central Statistics Office show that a total of 32,964 days were lost to industrial disputes last year.
The CSO said this compares with 44,015 days lost to disputes the previous year.
Three disputes in the education sector accounted for 73% of the days lost in 2015.
The CSO said there were a total of nine industrial disputes last year compared with eleven in 2014.
The nine disputes involved 37,760 workers and nine firms, compared to 31,665 workers and eleven firms involved in the industrial disputes in 2014.
