Here’s a list of books Hunter S. Thompson wrote but did not publish or which could be compiled from extant work. Also, there are some that he began but failed to complete.

• Prince Jellyfish – His first completed novel. Never published, but parts can be found in Songs of the Doomed.
• The Gun Lobby – A book-length essay about guns. A proto-Gonzo effort looking at the NRA.
• Guts Ball – Never actually completed, but Thompson worked on this novel for several years, making copious notes. The title was borrowed from Ken Kesey.
• Fear and Loathing in Elko – A proposed political book comprised of a Democratic manifesto with Thompson providing the introduction. This fell apart when the political figures involved could not reach any agreements.
• Galveston – A novel Thompson worked on for two years. It was about gunrunning in Texas.
• The Silk Road – Yet another attempt at a novel. Poorly written and ultimately never completed, parts were published in Songs of the Doomed.
• The Night Manager – This was a proposed book about Thompson’s time working at a strip club in San Francisco. It would be a novel, but based largely on real events. The was reportedly completed.
• The Rise of the Body Nazis – A book about so-called body fascism in the 1980s. Mostly, it would explore the idea of liberals jogging as a cult-like social phenomenon.
• 99 Days: The Trial of Hunter S. Thompson – This would have been the story of his trial for sexual assault in the early nineties.
• Polo is my Life – Thompson worked on this love story for many years and it was even given a release date, but he ultimately failed to finish it.
• Missives from the Mountaintop – Thompson’s letters have been hugely popular, with two of three editions already published. The third, however, has yet to appear and fans are largely giving up hope.
• The Short Stories – As a young man, Thompson laboured over his craft, writing lots of short stories and sending them to magazines. Only a handful were ever published. The rest could and should be collected and published.

There is a little more detail about some of these publications in this Mental Floss article and most of these books are discussed in detail in High White Notes.