In 1998, Sargent joined the ZDTV (later TechTV) TV show Call For Help as the show's "Resident Craft Professional" and substitute co-host. In 2001, he moved from Call For Help to another TechTV show, The Screen Savers, and became known first as "The Twisted Lister", for producing and presenting odd, "twisted" top-five lists on the show, and later for another segment, "Site of the Night", in which he presented strange websites.

Sargent left The Screen Savers in April 2003, to host his own show, Unscrewed with Martin Sargent, anchoring a newly introduced late-night programming block.

Six months later, on November 11, 2004, G4TechTV canceled Unscrewed and terminated Sargent, along with many other former co-workers from TechTV.

As of October 27, 2008 he was made redundant as part of Revision3 layoffs. He has reappeared on Revision3 show 'The Digg Reel' twice since he was laid off, once as acting co-host alongside Kevin Rose while regular host Andrew Bancroft was on vacation. In this appearance he expressed mock-anger that, as part of promotions within the show, other cancelled show 'Pixel Perfect' has been revived, unlike his own shows. He appeared once more on The Digg Reel's 100th episode, in which he jokingly stated that he secretly lived within the walls of the Revision3 building, resulting from his supposed inability to get another job.

In November 2009, Martin and long-time associate Molly McDonald became engaged.

Exactly one year after his termination, Sargent launched Infected, a comedy podcast distributed by the internet production company Revision3. Infected was hosted by Sargent and "The Gator" (portrayed by co-writer Jay Speiden, who died in December 2016), produced by Joey Rabier, and was structured as a conversation between co-hosts and Producer, with fake "commercials" for various real and fictional products as well as occasional guest callers. Recurring callers included Inventor Alex Chiu as well as the fictional characters Johnny O'Banion (portrayed by co-writer/producer Stewart Engesser), a Hollywood reporter and former Loni Anderson paramour, and karate master Rickey Kang (also played by Spieden). O'Banion and Kang were recurring characters on Infected, and Rabier acted as a production assistant on the show and also appeared as his "intern" character for selected skits. The podcast was originally available in audio-only format, then offered an alternative video version consisting of a montage of still photographs relating to the topic discussed and taken at the recording session. The video version has since been offered in full-motion video. Infected was canceled in December 2007, after 50 episodes.