The robber, described as a male Maori or Polynesian aged about 23, ran from the store after the robbery about 7pm on Saturday.
Police attempts to find the man were unsuccessful.
Detective Sergeant Brett Roberts, of Dunedin, said the man was wearing a black bandanna on his head, and a dark coloured jacket with a lighter coloured stripe. While he did not say he had a weapon, his mannerisms indicated to staff he did.
Video camera footage was expected to be released today.