Prendergast has appeared in The Bill, EastEnders, Holby City, Hotel Babylon, The Lightning Kid, Heartbeat, New Tricks, Emmerdale and Collision by Anthony Horowitz.
[2] As well as appearances in Casualty, Doctors, WPC 56, and Father Brown he plays the role of Robert Bain, the Head of Education for East Kilbride, in the drama series Waterloo Road.
[5] At Christmas in 2010 Prendergast played the role of Sarah the Cook in the pantomime Dick Whittington at the Lyric Theatre, Hammersmith, directed by Steve Marmion.
In early 2010 he played Mr Boo in The Rise and Fall of Little Voice by Jim Cartwright at the Vaudeville Theatre, London.
An article in The New York Times credited Prendergast's play as being the inspiration for the campaign to have Julia Pastrana repatriated to her birthplace.