A woman's honour was the cause of the dispute, according to a report from the Austrian Press Agency. The woman's photo had been shown around, which had angered her family.
"We haven’t yet found a weapon or weapons but a forensics team is examining the scene,” police spokesman Thomas Keiblinger told Radio Wien.
Four men are now in police custody and have been questioned by detectives. Police said that two Chechen families were involved.
"This dispute has been going on for some time and unfortunately escalated on Wednesday," Keiblinger said.
Eight men, between the ages of 20 and 49, are reported to have arrived in three cars and met near allotments in Floridsdorf at around 5pm.
Three of the men were shot and seriously injured and another man is thought to have been stabbed.
Two of the injured men fled with another man in a car but had to stop in Donaustadt and get medical help. They were taken to hospital and had emergency surgery.
Two injured men were discovered near to the allotments and also taken to hospital. All four men are being treated in different hospitals and are under armed guard.