A 29-year-old waiter was killed in Schum-les-Grand, about nine miles from downtown Paris, on Friday night, prosecutors in neighboring Bobini told CNN.
Witnesses say the man was angry about the length of time it took to prepare his sandwich, prosecutors confirmed.
Staff called police after a waiter was shot in the shoulder with a gun, according to AFP news agency.
The shooter escaped from the restaurant and the waiter died on the spot. Police have launched an investigation into the murder and the suspect is still on the run, according to prosecutors.
The locals expressed their shock at the incident.
"He was killed because of a sandwich?" he said, according to AFP.
"It's sad," a 29-year-old woman told AFP. "It's a quiet restaurant with no problems. It just opened a few months ago."
However, the surrounding area is known for high levels of crime, including drug trafficking and public drunkenness, according to AFP.
The Parisian suburbs, known as "gangs," have suffered years of political neglect and frequent police crackdowns.
In March, rumors on social media of abductions of children by members of the Roma ethnic minority triggered a wave of violence in France, although authorities dismissed the claims as unfounded.
The Roma were attacked in Bobini and Clichy-sous-Bois, another suburb northeast of Paris, as well as in Nanterre and Colombo.
(The-CNN-Wire & 201