The men targeted McGowans jewellers in New Kirk Road, Bearsden, East Dunbartonshire, at around noon today.
A window was smashed and a quantity of rings and bracelets were taken by the pair in what Police Scotland said was a "high value" theft.
No exact figure was available.
The first suspect is described as around 6ft 2in and with a heavy build, and he was wearing a black balaclava. He was also wearing a dark-coloured jacket and grey jogging trousers. The second suspect is around 5ft 5in and was wearing a black balaclava, purple jacket and black trousers.
It is thought they made off in a white Nissan 4x4 car.
There are a number of other stores in the street and officers are appealing to anyone who may have been in the area who may have noticed the two suspects prior to or following the incident to get in touch with them.