The Hells Angels brought a $5 million defamation lawsuit against Roger Corman for what they perceived as a negative portrayal of their image.
Actress Laura Dern (daughter of Bruce Dern and Diane Ladd) was conceived during the movie shoot. Growing up, she sometimes showed people who asked about her parents a still of them in their biker outfits.
George Chakiris was originally hired by Roger Corman to play "Black Jack" (later changed to "Heavenly Blues" by Peter Fonda), but insisted that a stunt double do his motorcycle riding, so Corman replaced him with Fonda, who was originally cast as "Loser".
Roger Corman paid the Hell's Angels $35 per day for their cooperation, and $20 per day for use of their motorcycles.