During the meeting scene between the Riders and Tigers near the Manhattan Bridge with the World Trade Center in background, the drummers seen playing were not originally scripted. The band was present in the area during the day of shooting, so director Enzo G. Castellari included them in the scene, giving no explanation as to why they were there.
This was Vic Morrow's last completed film before his unfortunate on-set death while filming Twilight Zone: The Movie (1983). In an eerily prescient scene that foreshadows his tragic death, Murrow's superior says to him, "If you don't get the girl by 11 o'clock tomorrow, I'll have your head!" Morrow's character replies, "We'll fly her in - in a helicopter."
The Iron Men gang were played by professional television dancers.
Feature debut of Mark Gregory (real name: Marco de Gregorio), who was 17 at the time. He was billed as Mark Gregory everywhere but in the Italian release, in which he was credited under his real name. Gregory had a noticeable stiff walking style, which allegedly became the subject of joking by The Hell's Angels on the set.