A man held a Tauranga shop attendant at gunpoint before leaving with "minimal cash".
The masked man entered Matua Dairy at 7.22pm on Friday.
After pulling a pistol on the attendant, he left the shop with a small amount of money and was last seen on Ranui Road.
Police are appealing for sightings of the offender.
He is believed to have spent time in the area before the robbery and police are interested in speaking to anyone who saw anything suspicious.
Anyone with information is asked to contact Tauranga police on 07 577 4300 or call Crimestoppers anonymously on 0800 555 111