And the odd thing for owner, Richard McIntyre, is that he did not even know he was in the running.
"It's just out of the blue."
Mr McIntyre owns Octagon Books, in Moray Pl and, according to the Irish Independent News, it is up there with the best of second-hand bookshops in Amsterdam, London, Paris, Mumbai and San Francisco.
Octagon Books was listed at No 7 by freelance Irish writer Derbhile Dromey, who suggested a visit was like "stepping back in time to a '50s English village".
Describing the shop, she wrote: "dust dances in the air", a cuckoo clock chimes the hour and the shelves are full of "comfortably musty tomes".
The tidy, and not particularly dusty or musty, little shop has been in its present location for more than six years, although it was previously at the back of the Athenaeum building in the Octagon.
Its shelves are stacked with books by still popular authors - Dr Seuss, Enid Blyton and Agatha Christie.
As well, there are many Otago histories.
All Aboard: The Ships and Trains that Served Lake Wakatipu, by R. J. Meyer, at $85, is one of the more expensive and displayed under glass.
But the shop's most distinguishing features are the things it does not have.
There is no telephone, computer, website or eftpos terminal.
The till rings up prices in pounds, shillings and pence and a bell sounds when the drawer pops open.
Mr McIntyre, originally from Greenhills, near Bluff, does not advertise and believes the shop is probably not well known in Dunedin.
He says most of his sales are to "out-of-town people".
He keeps a visitors' book for overseas customers but has no record of a visit by Derbhile Dromey.
Mr McIntyre, who lives at Broad Bay, has one eye on retirement, which he expects will pay better than being the proprietor of one of the 10 best second-hand bookshops in the world.
"You really don't make much money out of it.
"You have to do it because you like it."
The top 10
The top 10 second hand bookshops in the world, according to Irish Independent News: Amsterdam American Book Centre; Shakespeare and Company Bookshop, Paris; Smoker's Corner, Mumbai; Clarke's Bookshop, Cape Town; City Lights Bookshop, San Francisco; Basheer Graphic Books, Singapore; Octagon Books, Dunedin; London Review Bookshop; Boat Books, Sydney/Melbourne; Strand Bookshop, New York.
