He is best known for his stories and Wild West-style comic book art, and in particular, for his work on Grimjack (with John Ostrander), Scout, and the reinvention of Jonah Hex, with Joe R. Lansdale.

[citation needed] Along with Flint Henry, Truman co-authored Rifts Dimension Book 1: Wormwood (1993), which author Shannon Appelcline states was "critically acclaimed for the vibrant backgrounds".

[5] In 2015, Truman contributed, among other artists, to bring inner illustrations to the tabletop role-playing game Conan: Adventures in an Age Undreamed Of, first published in 2016 by British company Modiphius Entertainment.

He also worked on a typical pulp adventure Guns of the Dragon, featuring Enemy Ace and Bat Lash and scripted a Creature Commandos limited series.

[15][16][17][18] Truman's work, Wilderness: The True Story of Simon Girty, Renegade was a two-volume black and white graphic novel depicting the American settler's western frontier.

A longtime fan and musician, Truman has integrated his love of music into comics and illustration.

While writing the biography of one of his favorite guitarists, Carlos Santana, for Rock-It Comics, Truman found out that the musician had been a longtime fan of his comic, Scout, whose main character, Emanuel Santanna, is the namesake of the famous guitarist.

Truman provided illustrations for the posthumous Rory Gallagher release Kickback City (2013).

[21] Timothy Truman is often confused with the music composer Tim Truman[22] who wrote the theme to Melrose Place and composed the score to Miami Vice's final season among other important contributions to the music industry in movies and television.