A total of 1,127 working days were lost due to two industrial disputes involving 255 employees between April and June of this year, according to figures from the Central Statistics Office.
Virtually all of the losses were as a result of the Luas drivers' four-month pay dispute with their employer Transdev, which shut down the tram service for 12 days between February and May.
A majority of Luas drivers eventually accepted a Labour Court recommendation to end the dispute, which included wage increases of up to 18.3% and the reversal of cuts to drivers' benefits.
In total, 2,142 working days were lost during the four months of the Luas strike.
However, the number of working days lost during the second quarter was considerably lower than the same period last year, when 8,792 days were lost in three disputes involving more than 10,000 employees.
A Teachers' Union of Ireland one-day work stoppage in February - in protest over the effects of cuts on schools and its members - saw 3,454 days lost in a dispute than involved over 4,000 teachers.
The CSO data shows that last year just under 33,000 working days were lost as a result of disputes, while the figure for 2014 was above 44,000.
