Source novel author John le Carré appeared in this movie under his birth name David Cornwell and not as John le Carré. This film was the first appearance by le Carré in a filmed adaptation of one of his books. The second would be in Tinker Tailor Soldier Spy (2011) twenty-seven years later.
The film's source novel is one of author John Grisham's favorite novels. Grisham has said: "I love to read John le Carré, the British guy who's really probably my favorite writer. The Little Drummer Girl is a book I read about every four or five years. It's just so clever and brilliantly plotted. It's the kinda' book-and his writing is off the charts, the way he expresses himself and the way he describes people and dialogue - and every time I read that book, it inspires me to be better."
The lead role of Charlie played by Diane Keaton was originally intended to be an English woman. The Charlie character in John le Carré's source book is an English woman in her 20s whereas in this film she is an American woman in her 30s.
Attempting to break the typecasting Diane Keaton had fallen into, she took on the role of a confused, somewhat naive woman who becomes the tool of Middle Eastern terrorists in this movie.
John le Carré: The author of "The Little Drummer Girl" novel, appears as the policeman in the scene when Charlie goes to her London apartment. Le Carré was credited as David Cornwell, his birth name.