The Pearl-bordered Fritillary is once again fluttering between the boughs of Grafton Wood nature reserve near Worcester after 24 butterflies were released by Butterfly Conservation's West Midlands branch.
The butterfly has not been seen in Grafton Wood since the 1970s.
The release, assisted by Worcestershire Wildlife Trust, only came about because the trust and conservationists have spent the last five years creating a suitable habitat in the reserve near Grafton Flyford.
The released stock was bred in captivity by Butterfly Conservation members Trevor Bucknall and Nick Greatorex-Davies.
Mr Bucknall said: "Feeding several hundred hungry caterpillars was no easy task and I am delighted that we are now in a position to release the first butterflies into the wood."