The eight pieces were worth in the six-figure range, although the works were yet to be officially valued, gallery director Cam McCracken said.
Included were works by New Zealand artists Julian Dashper, who was awarded a senior Fulbright fellowship, and Giovanni Intra, a prominent artist, writer and art critic who died of an overdose in New York in 2002.
The Barrs are long-standing advocates of the arts in New Zealand and the Wellington collectors have had a relationship with the Dunedin gallery since 1997.
They have 120 works on long-term loan in Dunedin.
At last night's opening, which packed the gallery's foyer, Mary Barr said the couple wanted the works they had collected to be seen.
"We can't see them like this at home.''
Dunedin was a "really serious gallery'', with a collection built up over many years, she said.
The gallery started with donated works, and that was a tradition be encouraged.
Mr Barr said the pair had also provided works that might be more difficult to get with public money.
Mr McCracken said having the works gifted, rather than on loan, ensured the works would stay in Dunedin.
"They will stay here, and belong to the people of Dunedin.''
He described the pieces as "very significant works. They're a really solid addition to the gallery's collection.''
