Police responded to a report of a robbery at the store on Golf Club Road at around 4:20 a.m. Sunday.
Four masked suspects -- two carrying guns -- entered the store, went behind the counter and confronted the cashier, police said.
Police said the clerk, fearing for his safety, gave the suspects cash from the register and they fled on foot through the store parking lot.
The robbery mirrors three earlier robberies reported over the past month involving armed, masked suspects at late-night convenience stores in Pleasant Hill, Walnut Creek and Antioch.
Anyone with information about Sunday's armed robbery is asked to contact the Pleasant Hill Police Department's investigations unit at (925) 288-4630.