Officials said they received a call about the incident in Greenwood at 10:30 p.m.
The owner told troopers that while he was closing his business for the night, a man with a machete approached him and demanded money.
"The store owner advised the suspect that he did not have any money and threw a pizza at him, causing the suspect to flee," state police said.
The suspect then ran from the scene and got into a vehicle, driving off northbound on Sussex Highway.
The store owner did not sustain any injuries during the incident.
Anyone with information on the incident is asked to contact investigators at 302-337-8253. Information also may be provided by calling Delaware Crime Stoppers at 1-800-TIP-3333 or via the Delaware Crime Stoppers' website.