The man, described as 6-foot-2 and wearing a black wool hat, gray hooded sweatshirt and tan pants, robbed Fast Break Convenience Store on Merrick Avenue on Saturday at about 11 p.m., police said Sunday.
He asked a 36-year-old man working at the store for a pack of cigarettes, but then brandished a black handgun and demanded money from the register, police said.
The man then ran from the scene, and no one was injured in the incident, police said.
A store employee who did not want to be identified by name Sunday confirmed no one had been hurt in the incident. He said the suspect took only cash and only one employee was in the store at the time of the alleged robbery.
Detectives asked the anyone with information about the suspect or alleged crime contact Nassau County Crime Stoppers at 800-244-TIPS.