Around half the nurses who came here under the HSE's recruitment scheme have already left again, according to the INMO.
The HSE has spent €244,000 on the scheme since July 2015, attracting just 88 nurses.
The scheme is offering €1,500 to nurses in relocation fees, as well as access to post-grad education.
Documents released under the Freedom of Information Act show the HSE has given €200,000 to two recruitment firms in a bid to bring nurses back to Ireland.
They have spent a further €44,000 on advertising and a mini-website.
However, the spend does not seem to be working; the INMO says around 40 of the 88 nurses recruited have reportedly already left.
One newly qualified nurse, Aoife Kiernan, said it remained and issue of pay, but also of conditions and morale.
She said: "I actually never forgot on my very first day, one of the first nurses I met told me to stop, and get out. That's a very tough pill to swallow.
"I know a massive number of people planning to leave in January for packages in the UK or Australia, where you are started on more money, less hours and better working shifts, as well as a lower patient-nurse ratio which makes your environment safer and your overall working day better."
Aileen Mulvihil now works in a hospital in London, and says the HSE have not approached her about coming back
"I want to come home," she said, "but I've never seen anything that would say to me - 'You're an Irish nurse; here's what we'd offer you to come home.'"
There is competition from abroad for Irish nurses with foreign hospitals making good offers.
Private Irish hospitals are also offering sign-on bonuses for those returning, and payments to current staff who recommend a new nurse, which is making it hard for the HSE to compete.