The number of patients on trolleys at University Hospital Limerick actually fell last month, when compared with the same month lastyear.
However, over 500 people still found themselves waiting for admission across June, one of the highest numbers of any hospital in Ireland.
Throughout Ireland, the number of patients catalogued in the INMO's Trolleywatch stats fell by 32%.
The fall at Dooradoyle was slightly smaller than this, but the reduction here did see 141 fewer patients awaiting admission at the region's main hospital.
However, the total number of 512 means the hosptial recorded the second highest level of overcrowding of any hospital in the country last month.
Despite the smaller queues in June, the INMO are still flagging concerns about increased overcrowding this month.
Comparing last week with the same week in 2015, they've recorded a sharp jump in trolley numbers.
This has been reflected at University Hospital Limerick, where the numbers have gone from 87 last year to 149 this time around, the highest of any hospital in Ireland.
In releasing the figures, the Nurses and Midwives Organisation has re-iterated its call for the urgent recruitment of frontline staff.
