The Psychiatric Nurses Association has suspended this evening's planned industrial action by 6,000 of its members.
Nurses were due to begin an overtime ban from 7pm as part of their row with the HSE over the recruitment and retention of mental health staff.
This evening, the PNA says discussions with the Workplace Relations Commission has seen some of the issues resolved, while others will be referred to the Labour Court - which it has agreed to attend.
The union says more than 200 nursing posts have been granted to help tackle the reliance on overtime and agency staff in mental health services.
"There has been extensive engagement with the HSE over the last 24-hours," said Peter Hughes, General Secretary of the PNA.
"Following that we had a PNA board meeting today to consider our position. And some of the matters at hand have been addressed."