Four raiders stole cash, cigarettes and tobacco after breaking into the BP service station on Blackpool Road, Lea.
After grabbing the unspecified amount of money, tobacco, and cigarettes - mainly Lambert and Butler and Sterling Kingsize Dual cigarettes - they drove off in a Peugeot estate car towards Preston, police said.
Officers have now appealed for information on the burglary, which happened at around 1am on Wednesday, March 7.
The raiders were wearing gloves and had their faces covered, and used a white builder's sling to carry their loot to the car, the force said.
Police were alerted around 20 minutes later, and are keen to trace three people stood outside the Johney Rockets takeaway, also in Blackpool Road, at around the time of the break-in.
PC Kurt Edwards from Preston CID said: "Were you in the area at the time of the incident? Do you recognise these people?
"They could hold vital information to aid our investigation and I’d urge anyone with information to contact the police. I’d also like to ask that anyone who is aware of the sale of bulk cigarettes since March 7, to let us know.”
Police can be contacted on 101 quoting log number 49 of 7th March.