Thompson, who had a number of run-ins with the law as a young man, joined the U.S. Air Force in 1956. He served as a sports editor for a base newspaper and continued his journalism career after being discharged in 1957. In 1965 he infiltrated the Hell's Angels motorcycle gang, an experience he recounted in Hell's Angels (1967). The book led to writing assignments for Esquire, Harper's, Rolling Stone, and other magazines. In addition to his irreverent political and cultural criticism, Thompson also began to attract attention for his larger-than-life persona, which was highlighted by drug- and alcohol-fueled adventures and a distaste for authority.

In 1970 Thompson introduced his subjective style of reporting with the article The Kentucky Derby Is Decadent and Depraved, in which he was a central part of the story. A 1971 assignment for Sports Illustrated to cover a motorcycle race in Nevada resulted in perhaps his best-known work, Fear and Loathing in Las Vegas: A Savage Journey to the Heart of the American Dream (1972; film, 1998), which became a contemporary classic and established the genre of gonzo journalism. First serialized in Rolling Stone, it documents the drug-addled road trip taken by Thompson (as his alter ego Raoul Duke) and his lawyer (Dr. Gonzo) while also discussing the end of the 1960s counterculture. The book featured frenetic artwork by Ralph Steadman, who illustrated many of Thompson's works. In Fear and Loathing: On the Campaign Trail '72 (1973), Thompson chronicled the 1972 presidential campaigns of George McGovern and Richard Nixon. Later works include The Great Shark Hunt (1979), Better Than Sex (1994), and Kingdom of Fear (2003). Thompson died of a self-inflicted gunshot wound.