In 1937 he was transferred to the new BBC television service at Alexandra Palace, adapting a J. M. Barrie one act play, "The Old Lady Shows Her Medals", for release in December of that year.

[10] That year he also played a Detective Superintendent in the Ealing Studios comedy film, The Lavender Hill Mob, directed by Charles Crichton, and starring Alec Guinness and Stanley Holloway.

Kelsall then made an appearance as "MacCauley" in Errol Flynn's 1953 Scottish swashbuckler, The Master of Ballantrae,[12] and, in the same year, played Commander Dawson in the wartime POW movie, Albert R.N., about the use of a dummy to disguise the escape of a prisoner.

[15] Kelsall took time out in 1956 to write, adapting for TV a Marie Fawcett story, Mister Betts Runs Away, in the ATV series "Lilli Palmer Theatre".

Before its release, this film was entirely voiced over by different actors to those who appeared in it, and Kelsall provided the audio presence for the district commissioner, who had been visually played by Tony Blane.

Between 1961 and 1969, Kelsall switched mainly to the medium of television, securing roles in various BBC anthology-style series, such as Suspense and Out of the Unknown, and other more mainstream sixties productions, including appearances in The Saint and Dr. Finlay's Casebook.

Kelsall took the part of boarding house owner Petey Bowles in the 1968 film version of Harold Pinter's The Birthday Party, which starred Robert Shaw.

[28] After appearing as Tradul in 1977 in a BBC television adaptation of Rosemary Sutcliff's Roman saga, The Eagle of the Ninth (starring Patrick Malahide), Kelsall went into semi-retirement.

[29] He made one final contribution to television, taking the part of Sir Archie in BBC TV's adaptation of the Henrik Ibsen novel, Enemy of the People, which featured Robert Urquhart, and which was broadcast ten days before Moultrie Kelsall died on 13 February 1980.