Because of his strapping build, commanding height (6 ft 4 in or 1.93 m) and regimental demeanour he would often be found playing military types and men of action in such classic 1960s films as Jason and the Argonauts, Zulu, Tobruk and The Ipcress File.

At the Stratford Memorial Theatre in 1950, he was cast as Sir Thomas Lovell in Henry VIII (directed by Tyrone Guthrie), Abhorson in Peter Brook's production of Measure for Measure (which also went on tour in Germany), Decius Brutus in Julius Caesar (directed by Anthony Quayle), and — most notably — Edmund in King Lear, starring and co-directed by John Gielgud.

[10] In his second volume of autobiography, Michael Powell pointed out that, though the play they collaborated on was a failure, "Nigel Green, with his great face and towering figure, would soon make a name for himself in movies.

Among other men they were like Norse gods, mythical, large and gentle, suddenly exploding into rage and performing fabulous feats of strength.

[16] Green also appeared in a number of horror films, including Corridors of Blood (1958), The Masque of the Red Death (1964), The Skull (1965), Let's Kill Uncle (1966) and Countess Dracula (1971).