McQuarrie initially worked for a dentistry firm, illustrating teeth and equipment,[1] before working as an Artist and Preliminary Design Illustrator for the Boeing Company, where he drew diagrams for a manual on constructing the 747 Jumbo Jet, as well as designing film posters and animating CBS News' coverage of the Apollo space program at the three-man company Reel Three.

Lucas sought visual reference material to support his pitch to film studios and purchased pieces of science fiction artwork by John Berkey.

[13] In an interview with Star Wars Insider Magazine, McQuarrie stated that Lucas' artistic direction was to portray a malevolent figure in a cape with samurai armour.

Lucas agreed, and McQuarrie combined a full-face breathing mask with a samurai helmet, thus creating one of the most iconic designs of space fantasy cinema.

The first edition of Star Wars: From the Adventures of Luke Skywalker went to press in 1976 featuring McQuarrie's version of Darth Vader's helmet on the cover.

Titled Star Trek: Planet of the Titans, the film was to feature a redesigned USS Enterprise starship, and McQuarrie was recruited to provide the visualizations.

[18] When Lucas began work on his sequel to Star Wars, The Empire Strikes Back (1980), McQuarrie was once again brought in to supply previsualization artwork.

His sketches and production paintings established the appearance of some of the saga's most enduring elements, such as the gigantic AT-AT Walkers in the battle on the ice planet Hoth and the wizened elf creature Yoda.

[1][9] Action figures were also produced based on McQuarrie's concept art, including conceptual versions of the Imperial Stormtrooper, Chewbacca, R2-D2 and C-3PO, Darth Vader, Han Solo, Boba Fett, Obi-Wan Kenobi, Yoda and other characters.

[9][21] He also worked on the 1978 TV series Battlestar Galactica,[9] and the films Raiders of the Lost Ark, Star Trek IV: The Voyage Home and *batteries not included.

[6] Rick McCallum offered McQuarrie a role as designer for the Star Wars prequel trilogy, but he declined, noting he had "run out of steam" and Industrial Light & Magic animator Doug Chiang was appointed instead.

[1][6][9] Christian Blauvelt of Entertainment Weekly praised McQuarrie's works as "pioneering of the 'used future' aesthetic" which unlike other science-fiction, "imagined a lived-in galaxy that was gritty, dirty, and in advance states of decay."

A McQuarrie Star Wars design looks like what would have resulted if Salvador Dalí had sketched concepts for Universal's 1936 Flash Gordon serial by way of Sergio Leone's Old West.

"[3] After McQuarrie's death, George Lucas said: "His genial contribution, in the form of unequalled production paintings, propelled and inspired all of the cast and crew of the original Star Wars trilogy.

"[27] The current Lucasfilm creative team is employing parts of McQuarrie's original unused concept art from the seventies and eighties in the development of new Star Wars-related media.