A fight broke out between the two men at 3am on Saturday morning in the fast-food restaurant on Stachus-Platz, close to Munich's old town centre.
According to a report in Swiss newspaper Blick, the 41-year-old Giacomo A. was seriously injured after he fell to the floor. He was taken unconscious to a nearby hospital and underwent an emergency operation, but died of his injuries on Saturday at midday.
Reports say Giacomo A. did not know the unnamed 24-year-old Austrian. But they were sitting at the same table, where he began flirting with the Austrian's girlfriend.
Witnesses say a fight broke out when the Swiss man bit into the girl's burger. The Austrian allegedly kicked him several times in the head.
The Stachus-Platz restaurant, which is open 24 hours a day, is one of the biggest and busiest McDonald's branches in Europe, and is a central meeting place for Munich partygoers.
Giacomo A. was a businessman who had been living in Munich for several years. An autopsy is currently taking place to determine the exact cause of his death, particularly whether the injuries that killed him were inflicted before or in his fall.
The suspected perpetrator was arrested at the scene and questioned by police. He is said to be unemployed and also a long-term Munich resident. Police say he faces charges of bodily harm with lethal consequences.