Nine magnificent birds, which were among 20 recently brought in from Norway, were set free by project director Dr Allan Mee in the presence of about 30 onlookers, including tourism interests and bird-watchers.
Conditions were perfect and all of the birds flew downwind in the direction of Killarney Lakes. The birds, born last spring, were all said to be strong and healthy and fit for survival in the wild.
The plan had been to release 10, and nine of them appeared rearing to go as soon as the cages were opened.
But one, nicknamed Star after Kerry footballer Kieran Donaghy, refused to budge. However, it will take off in its own time, according to Dr Mee, and the remaining 10 will be released in the coming weeks.
Since arriving in Killarney in late June, the birds had been kept in secluded cages and were fed on a diet that included fish and venison. Food will be left out for them at various points around the lakes for a few months and they will then have to fend for themselves.
So far, 44 eagles have been released in Killarney. The project was started two years ago and will involve the release around 100 eagles in the hope that some will eventually breed.
The instinct of the birds is to head towards the sea. Some of those released earlier have been tracked to Northern Ireland, while one went as far as the Orkney Islands, off north- west Scotland.
Poisoning, however, remains a concern. Eight of the birds have died, with poisoning confirmed as the reason for five of the deaths in the past two years.
Dr Mee has warned that if the poisonings continued, the entire project would be seriously undermined.
He renewed his appeal to farmers not to put out poisoned meat bait, normally used to kill pests such as crows and foxes.