There were 8,486 days lost to industrial disputes last year, according to figures from the Central Statistics Office.
That is a significant rise on 2011, when 3,695 days were lost.
The CSO figures show that there were five disputes in progress during 2012, which involved 1,920 a total of workers.
Two of these disputes accounted for 6,114, or 72%, of the days lost.
Despite the year-on-year increase no days were lost to industrial action during the final three months of last year. This represents the first quarter where no days were lost since Q3 2007.
