However, she does have her detractors, most notably the American novelist Raymond Chandler, who criticised her in his essay, "The Simple Art of Murder", and the American literary critic Edmund Wilson, who was dismissive of Christie and the detective fiction genre generally in his New Yorker essay, "Who Cares Who Killed Roger Ackroyd?".

Others have criticized Christie on political grounds, particularly with respect to her conversations about and portrayals of Jews. Christopher Hitchens, in his autobiography, describes a dinner with Christie and her husband, Lord Mallowan, which became increasingly uncomfortable as the night wore on, and where "the anti-Jewish flavor of the talk was not to be ignored or overlooked." Critic Johann Hari notes "In its ugliest moments, Christie’s conservatism crossed over into a contempt for Jews, who are so often associated with rationalist political philosophies and a ‘cosmopolitanism’ that is antithetical to the Burkean paradigm of the English village. There is a streak of anti-Semitism running through the pre-1950s novels which cannot be denied even by her admirers."

Christie occasionally inserted stereotyped descriptions of characters into her work, particularly before the end of the Second World War (when such attitudes were more commonly expressed publicly), and particularly in regard to Italians, Jews, and non-Europeans. For example, in the first editions of the collection The Mysterious Mr Quin (1930), in the short story "The Soul of the Croupier," she described "Hebraic men with hook-noses wearing rather flamboyant jewellery"; in later editions the passage was edited to describe "sallow men" wearing same. To contrast with the more stereotyped descriptions, Christie often characterised the "foreigners" in such a way as to make the reader understand and sympathise with them; this is particularly true of her Jewish characters, who are seldom actually criminals. (See, for example, the character of Oliver Manders in Three Act Tragedy.)

Christie has been portrayed on a number of occasions in film and television.

Several biographical programs have been made, such as the 2004 BBC television program entitled Agatha Christie: A Life in Pictures, in which she is portrayed by Olivia Williams, Anna Massey, and Bonnie Wright.

Christie has also been portrayed fictionally. Some of these have explored and offered accounts of Christie's disappearance in 1926, including the 1979 film Agatha (with Vanessa Redgrave, where she sneaks away to plan revenge against her husband) and the Doctor Who episode "The Unicorn and the Wasp" (with Fenella Woolgar, her disappearance being the result of her suffering a temporary breakdown due to a brief psychic link being formed between her and an alien). Others, such as 1980 Hungarian film, Kojak Budapesten (not to be confused with the 1986 comedy by the same name) create their own scenarios involving Christie's criminal skill. In the 1986 TV play, Murder by the Book, Christie herself (Peggy Ashcroft) murdered one of her fictional-turned-real characters, Poirot. The heroine of Liar-Soft's 2008 visual novel Shikkoku no Sharnoth ~What a beautiful tomorrow~, Mary Clarissa Christie, is based on the real-life Christie.

Christie has also been parodied on screen, such as in the film Murder by Indecision, which featured the character "Agatha Crispy".

See List of works by Agatha Christie

These three novels are now available in the collection Murder In Three Stages.