The man entered the Riverside Plaza store at about 4pm on Saturday, April 11 and asked to see a selection of gold chains.

He grabbed them and ran off in the direction of the shopping centre's underground car park.

A female sales assistant gave chase but he entered a Toyota Prado and drove off in the direction of Collett Street. Queanbeyan Police said the vehicle had ACT registration plates.

The man was described as 25 - 30-years-old, caucasian and 170 - 175 cm tall. He had short brown hair, blue eyes and a distinctive Southern Cross tattoo on his left forearm.

Queanbeyan duty officer Michael Handley said police were currently reviewing CCTV footage of the incident.

"It's not often these things happen but obviously being a jeweller, these items are quite valuable," he said.

"[The robber] has taken the opportunity and run off with the chains. We believe there was someone in the car who drove him away."

The Queanbeyan Age contacted the manager of Prouds the Jewellers who declined to comment as a matter of company policy. They said the criminal matter had been referred to police.

It's not the first time a thief has done a 'snatch and grab' at a local jeweller.

Three years ago, another jeweller - also based in Riverside Plaza - had a valuable $6000 engagement ring stolen in similar circumstances.

A man entered Dimitries Jewellers in September, 2012 asking to purchase a yellow gold ring with ten diamonds on the band.

As the assistant rung up the sale, the thief asked to have one last look at the ring, slipped it on his finger and ran out of the store.

The store had 13 security cameras at the time of the incident and released images of the thief but he was never caught.

Anyone with any information can contact the Queanbeyan Police on 6298 5055 or Crime Stoppers on 1800 333 000.