An armed man held up the Reflections Food-4-Less store on MacLendon Drive in George Town during the pre-dawn hours Thursday.
According to the Royal Cayman Islands Police Service, a man with his faced covered brandished a handgun inside the store and demanded cash.
Police said he took some money from the store register and ran off across Shedden Road toward the Mango Tree Bar.
No one was hurt and no shots were fired, police said.
Police described the suspect as about 5 feet, 5 inches tall, with a light brown complexion, wearing a black shirt and baseball cap over his head.
Anyone with information is asked to call George Town Police Station at 949-4222, the RCIPS anonymous tip line at 949-7777 or Cayman Crime Stoppers at 800-8477.