Antipodes Island has been cleared of its estimated 200,000-strong mouse population.
Conservation Minister Eugenie Sage has declared the island officially mouse free.
Mice arrived on Antipodes Island, 820km southeast of New Zealand, on shipwrecks and sealing ships in the 1800s.
Since then they have wiped out two species of insect and pushed some sea birds to breed on nearby pest-free islands.
A $4 million project to get rid of the mice started in 2014. Eradication work got underway in 2016.
Ms Sage said a Department of Conservation team spent a month searching the island for rodents and returned to Dunedin yesterday announcing they had found none.
"This is huge news for conservation both in New Zealand and internationally," Ms Sage said.
Ms Sage said 21 species of breeding sea bird, four unique land birds, and more than 150 species of insect were found on Antipodes Island.
"They can now thrive with mice no longer preying on the insects or competing with the land birds," she said.