Officials say it happened around 12:16 p.m. Tuesday outside of an AutoZone in Chester, Pennsylvania, a suburb of Philadelphia.
The brazen crime happened only a hundred yards away from the Chester Police Department headquarters.
One of the suspects, wearing a blue public safety jacket, and the other suspect, in a reflective jacket, held up the driver with long guns and assaulted him.
Police say the two men got away with hundreds of thousands of dollars.
Investigators say the driver was not injured during the robbery.
Authorities say the suspects arrived and fled in a Nissan Pathfinder bearing a laminated paper tag of LLN-2328. The vehicle has black trim around the license plate, black rims and a roof rack.
There's a nearly identical vehicle that bears the same Pennsylvania tag number on a real license plate, authorities said. This vehicle is not involved in the robbery. It is described as having no roof rack and a white CarMax sticker above the left rear tail light.
The suspects are reportedly still armed. Anyone who spots them should dial 911 immediately.
This is at least the third incident involving an armored truck in the Philadelphia area in the past year.
In March, three suspects held up a security guard driving a Loomis armored truck in Philadelphia's West Oak Lane neighborhood. The group assaulted the driver before getting away with her weapon and $2,500.
And last October, another Brinks driver was shot by two suspects who got away with his weapon and a bag of money as the driver was making a delivery at a Bank of America on Columbus Boulevard in South Philadelphia.
Anyone with information on the theft is asked to call police at 610-891-5337.