MacTaggart was born in Glasgow and served in the Royal Army Service Corps from 1946, rising to the rank of Captain by the time he was demobbed in 1949.
[2] After his involvement with such series as Storyboard (1961), wholly written by Kennedy Martin, and Studio 4 (1962), MacTaggart was given the responsibility of producing the second season of The Wednesday Play.
[citation needed] MacTaggart directed later productions during the anthology series' run and also instalments in its successor, Play for Today.
MacTaggart joined Kestrel Productions, established by Kenith Trodd, Tony Garnett and Ken Loach, which had an arrangement with the new ITV contractor London Weekend Television, and directed Dennis Potter's Moonlight on the Highway (1969), with Ian Holm in the play's leading role, and Simon Gray's Pig in the Poke (also 1969).
[4] In an interview for The Guardian published in October 2019, Ken Loach said of MacTaggart: "Jimmy was an iconoclast, constantly trying to knock down authority.