Only works written by Christie (including short stories, the novels and her play Black Coffee) are considered canon by most fans and biographers.

The Poirot books are still under copyright in the United Kingdom. The Mysterious Affair at Styles, The Murder on the Links and Poirot Investigates are now public domain in the US but will not become public domain in the UK until 2046 (70 years after Christie's death). Christie's grandson, Mathew Prichard, now owns the copyright to his grandmother's works.

In 2013, the Christie estate authorised author Sophie Hannah to write a new Poirot book, The Monogram Murders (2014). She later also wrote Closed Casket (2016), The Mystery of Three Quarters (2018), The Killings at Kingfisher Hill (2020) and Hercule Poirot's Silent Night (2023).

• "The Chocolate Box" (short story from Poirot's Early Cases)
• The Mysterious Affair at Styles
• "The Affair at the Victory Ball" (short story from Poirot's Early Cases)
• "The Kidnapped Prime Minister" (short story from Poirot Investigates)
Poirot settles down in London and opens a private detective agency. These are the short story years (26 short stories and only 4 novels).
• "The Jewel Robbery at the Grand Metropolitan" (short story from Poirot Investigates)
• "The King of Clubs" (short story from Poirot's Early Cases)
• "The Disappearance of Mr Davenheim" (short story from Poirot Investigates)
• "The Plymouth Express" (short story from Poirot's Early Cases)
• "The Adventure of the Western Star" (short story from Poirot Investigates)
• "The Tragedy at Marsdon Manor" (short story from Poirot Investigates)
• "The Million Dollar Bond Robbery" (short story from Poirot Investigates)
• "The Adventure of the Cheap Flat" (short story from Poirot Investigates)
• "The Mystery of the Hunters Lodge" (short story from Poirot Investigates)
• "The Adventure of the Egyptian Tomb" (short story from Poirot Investigates)
• "The Veiled Lady" (short story from Poirot's Early Cases)
• "The Adventure of Johnny Waverly" (short story from Poirot's Early Cases)
• "The Market Basing Mystery" (short story from Poirot's Early Cases)
• "The Adventure of the Italian Nobleman" (short story from Poirot Investigates)
• "The Case of the Missing Will" (short story from Poirot Investigates)
• "The Submarine Plans" (short story from Poirot's Early Cases)
• "The Adventure of the Clapham Cook" (short story from Poirot's Early Cases)
• "The Lost Mine" (short story from Poirot's Early Cases)
• "The Cornish Mystery" (short story from Poirot's Early Cases)
• "The Double Clue" (short story from Poirot's Early Cases)
• "The Lemesurier Inheritance" (short story from Poirot's Early Cases)
• "Double Sin" (short story from Poirot's Early Cases)
• Murder on the Links

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Some Poirot adventures were later expanded into other stories or re-written. They are:
• The Plymouth Express (1923 short story) was expanded into the 1928 novel The Mystery of the Blue Train
• The Market Basing Mystery (1923 short story) was expanded into the 1936 novella Murder In The Mews
• The Submarine Plans (1923 short story) was expanded into the 1937 novella The Incredible Theft
• Christmas Adventure (1923 short story) was expanded into the 1960 novella The Adventure of the Christmas Pudding
• The Mystery of the Baghdad Chest (1932 short story) was expanded into the 1960 novella The Mystery of the Spanish Chest
• The Second Gong (1932 short story) was expanded into the 1937 novella Dead Man's Mirror
• The Regatta Mystery (1936 short story) was re-written in 1939 featuring Parker Pyne instead of Poirot
• Yellow Iris (1937 short story) was expanded into the 1945 novel Sparkling Cyanide featuring Col. John Race instead of Poirot
• Hercule Poirot and the Greenshore Folly (posthumous novella ) expanded into the 1956 novel Dead Man's Folly
• The Incident of the Dog's Ball (posthumous short story) expanded into the 1937 novel Dumb Witness
• The Capture of Cerberus (posthumous short story), originally intended to be the last of The Labours of Hercules but re-written due to its political content
Other stories were adapted by Christie into plays, sometimes removing Poirot:
• Alibi (1928 play) written together with Michael Morton
• Wasp's Nest (1937 TV play)
• The Yellow Iris (1937 radio play)
• Appointment with Death (1945 play) in which Poirot doesn't appear
• Hidden Horizon (1944 play) in which Poirot doesn't appear
• The Hollow (1951 play) in which Poirot doesn't appear
In addition, the 1930 play Black Coffee was novelized by Charles Osborne in 1998.