He was best known for his work on the television series MythBusters, on which he designed, built and operated numerous robots and machines to test myths over the course of the show.

Imahara was also a chief model maker with Industrial Light & Magic (ILM) on such movie projects as Galaxy Quest.

He starred in the 2016 Netflix series White Rabbit Project alongside his MythBusters co-stars Kari Byron and Tory Belleci.

[4] For a time, he considered switching majors with the intention of becoming a screenwriter, but he decided to stay on the engineering track after assisting Tomlinson Holman, a professor at the USC School of Cinematic Arts.

While at ILM, he was involved in several films, including The Lost World: Jurassic Park, Star Wars: Episode I – The Phantom Menace, Galaxy Quest, A.I.

He joined as the third member of the Build Team alongside Kari Byron and Tory Belleci, replacing former MythBusters welder Scottie Chapman.

[10] Imahara reunited with Byron and Belleci for the 2016 White Rabbit Project, a Netflix Original Series, in which the team investigated topics such as jailbreaks, superpower technology, heists, and bizarre World War II weapons, evaluated against a defined set of criteria and explored through experiments, builds, and tests.

Other works include designing the circuit that creates the rhythmic oscillation of the arms of the modern Energizer Bunny;[7] leading Team ILM to victory in an appearance on Junkyard Mega-Wars; and authoring Kickin' Bot: An Illustrated Guide to Building Combat Robots (ISBN 0-7645-4113-7)[7] Imahara was a cast member and story writer for the short film Architects of Evil, created for the 2004 Industrial Light & Magic Backyard Film Contest.

[19] In 2012, Imahara's likeness was used in the popular webcomic America Jr, in which he appeared as himself as a celebrity judge for a competition to select the country's Surgeon General.

[20] In 2012, Imahara had a cameo role on the finale of Eureka, in the episode titled "Just Another Day", as a robotics scientist operating EMO.

[21][unreliable source] Imahara portrayed Hikaru Sulu in all 11 episodes of the web series Star Trek Continues.

[38] On October 23, 2020, on what would have been his 50th birthday, the Grant Imahara STEAM Foundation was announced by his mother, professional colleagues, and friends (including Mythbusters castmates Kari Byron, Tory Belleci and Adam Savage).

Imahara Joe is a tinkerer who helps the main characters build mechanical automaton motorbikes to achieve their goals.