The Berliner Morgenpost newspaper said members of the gang were sitting outside their club house in Berlin's Wedding district at 3 a.m. when the man and his 17-year-old son drove by in a white Audi.
What followed was a high-speed chase involving three Hells Angels cars.
"When the Italians' Audi stopped, the Hells Angels jumped out of their a cars and started hitting the victims' car with baseball bats, axe handles and telescopic batons," a police officer told the paper.
Two gang members repeatedly tried to stab the driver's son through the passenger window, which had been damaged. The 17-year-old was not injured in the attack.
His father rammed into one of the Hells Angels' trying to escape, but the attackers did not follow him. A short time later, the two victims arrived at a police station to report the incident.
Berliner Morgenpost said the investigation showed that neither of the two victims had any contact with the Hells Angels in the past.
An officer said the fact that the attack seemed to have been motivated purely by a lust for violence underscored how dangerous the group is.
The incident followed a series of fights between rival motorcycle gangs, and multiple arrests on charges of drug dealing and violent crime.