It was Thompson's first published book and his first attempt at a nonfiction novel. Thompson had previously written two unpublished fictional novels, one of which was eventually published in 1998.
The book's epigraph is a translation of François Villon's 15th-century poem Ballade du concours de Blois:
Thompson spent the next year preparing for the new book in close quarters with the Hells Angels, in particular the San Bernadino and Oakland chapters of the club and their president Ralph "Sonny" Barger. Thompson was up front with the Angels about his role as a journalist, a dangerous move given their marked distrust of reporters from what the club considered to be bad press. Thompson was introduced to the gang by Birney Jarvis, a former club member and, at the time, police-beat reporter for the San Francisco Chronicle. This introduction, coming from an Angel and reporter allowed Thompson to get close to the gang where so many others had failed.
Far from being wary of this outsider the Angels were sincere in their participation, often talking at length into Thompson's tape recorder and reviewing early drafts of the article to ensure he had his facts straight. The gang often visited his apartment at 318 Parnassus in San Francisco, much to the dismay of his wife and neighbors. Thompson, however, felt comfortable with the arrangement, having warned the bikers that he "didn't go much for fist-fighting but preferred to settle his beefs with a double-barreled 12-gauge shotgun" which he promptly displayed to them.
Thompson remained close with the Angels for a year, though ultimately the relationship broke down when several members of the gang gave him a savage beating, or "stomping" as the bikers referred to it. Thompson ended his time with the gang at this point, though he would later note in letters to friends and to Sonny Barger that the Angels who had participated in the beating had not been those with whom he had most closely associated. Because of this he continued to think warmly of Barger and other members of the club, such as Terry the Tramp, who had not been involved.
Thompson's flippant treatment of gang-rape by Hells Angels, a practice which the bikers in his book commonly engaged in, was strongly criticized by radical feminist Susan Brownmiller in her own book, 1975's Against Our Will: Men, Women, and Rape.