Loosely based on the early life of Guy Burgess, a key figure in the Cambridge Five spy ring of the 1930s and 1940s, who eventually defected to Russia in 1951. Even the manner of "Guy Bennett"'s father's death, as he discloses it to Harcourt, is the same as Burgess's father. Even so, the closing credits make the standard declaration, "The events, characters and firms depicted in this photoplay are fictitious. Any similarity to actual persons, living or dead, or to actual firms is purely coincidental."
Eton College reportedly declined to allow filming at the school.
In the original West End play of "Another Country" that ran in London in 1982, Kenneth Branagh, at age 22, originated and played the part of Judd. In the movie the part was given to Colin Firth. Firth had also been in the original play but had played the character Bennett. Rupert Everett repeated the same role he had played on stage. Ironically, it had been Branagh who won the Society of West End Theatre award that year for 'Most Promising Newcomer' for his part in the play. Later Firth and Branagh would co-star in A Month in the Country (1987) and Conspiracy (2001).
In his 2007 autobiography, Rupert Everett claims that he and Colin Firth formed a serious dislike of one another. True or false, they played close friends again in The Importance of Being Earnest (2002), as well as co-starring in Shakespeare in Love (1998), St. Trinian's (2007) and St Trinian's 2: The Legend of Fritton's Gold (2009), and Everett cast Firth in his debut as writer and director, The Happy Prince (2018).
A fountain was added to Brasenose College specifically for the film.