Seven unidentified men intercepted and opened fire at the van, injuring the driver near Banur town in the district, a senior police official said.
"The incident occurred when the van was on its way from Chandigarh to distribute cash to some branches in Banur and Rajpura," Patiala SSP S Bhupathi said.
The robbers chased the van for some time and intercepted it on the highway, he said.
The injured driver has been hospitalised.
"We have registered a case under relevant provisions of the law," the SSP said.