Roy Holmes, 58, made off with hundreds of pounds of tobacco and cash after waving a lock-knife at staff in two North Yorkshire filling stations.
He also targeted a Co-op store near Keighley.
CID detectives launched an investigation after the first incident at ASDA Express on Wetherby Road, Knaresborough.
They carried out extensive enquiries including a public appeal for information using CCTV images of the crime.
Holmes, of Park Side Road, Bradford, brandished a knife during the incident in June before leaving with tobacco products and a small amount of cash.
He was arrested following a similar incident at Woodlands Service Station on Wetherby Road, Harrogate a number of weeks later.
During that incident, Holmes put fuel in a car which was on false numberplates, then went into the shop and filled a bag with cigarettes as he held staff at knifepoint.
As he made his getaway, the car was stopped by North Yorkshire Police officers who had traced it to the outskirts of Bradford.
They searched the vehicle and found the stolen items, a knife and fake numberplates.
Holmes was arrested, charged with robbery and remanded in custody.
Detectives linked him to the previous robbery in Knaresborough, as well as one at a Co-op in Cullingworth near Keighley last September.
He pleaded guilty to all three of the robberies.
A judge at York Crown Court today sentenced Holmes to six years in prison.
Speaking afterwards, Police Investigator David Carter who worked extensively on the investigation, said:
During interview Holmes refused to speak – he showed no accountability and no remorse to his victims, whose courage I would like to acknowledge today.
This was a joint effort by two CID teams who worked relentlessly to secure today’s conviction.
While crimes like this are thankfully rare in North Yorkshire, they are very frightening for victims so I’m glad justice has been served and Holmes is behind bars.
